Refactor TestDataConnectionSql into focused partial modules

[Copilot]

TestDataConnectionSql.cs had grown into a 900+ line, multi-responsibility file spanning connection lifecycle, quoting, name parsing, schema discovery, and data reads. This change separates those concerns into focused partial-class files while preserving the existing API surface and NETFRAMEWORK-only behavior.

• Core lifecycle

  • Kept construction, provider factory setup, connection state handling, metadata defaults, and Dispose in TestDataConnectionSql.cs.
  • Left the class entry point and factory method unchanged.

• Quoting and identifier handling

  • Moved quote prefix/suffix resolution and provider-specific identifier quoting logic into TestDataConnectionSql.Quotes.cs.
  • Split name parsing / re-quoting mechanics into TestDataConnectionSql.Names.cs to isolate identifier normalization from provider quote discovery.

• Schema inspection

  • Moved default-schema lookup, table/view enumeration, column lookup, and display-name formatting into TestDataConnectionSql.Schema.cs.
  • Kept the existing schema query flow and helper behavior intact.

• Data access

  • Moved ReadTable and column projection SQL generation into TestDataConnectionSql.Data.cs.

• Shared helpers and constants

  • Moved SQL-provider helpers, schema metadata types, and known OLE DB / ODBC provider constants into TestDataConnectionSql.Helpers.cs.

Example of the new structure:

internal partial class TestDataConnectionSql : TestDataConnection
{
    // TestDataConnectionSql.cs
}

internal partial class TestDataConnectionSql
{
    // TestDataConnectionSql.Quotes.cs
    // TestDataConnectionSql.Names.cs
    // TestDataConnectionSql.Schema.cs
    // TestDataConnectionSql.Data.cs
    // TestDataConnectionSql.Helpers.cs
}

[Evangelink]

@copilot fix the following build issues

@azure-pipelines
azure-pipelines
/ microsoft.testfx (Build Windows Debug)
src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Data.cs#L78

src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Data.cs(78,17): error CS0103: (NETCORE_ENGINEERING_TELEMETRY=Build) The name 'StringEx' does not exist in the current context
Check failure on line 23 in src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Helpers.cs

@azure-pipelines
azure-pipelines
/ microsoft.testfx (Build Windows Debug)
src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Helpers.cs#L23

src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Helpers.cs(23,61): error CS0103: (NETCORE_ENGINEERING_TELEMETRY=Build) The name 'StringEx' does not exist in the current context
Check failure on line 276 in src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Schema.cs

@azure-pipelines
azure-pipelines
/ microsoft.testfx (Build Windows Debug)
src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Schema.cs#L276

src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Schema.cs(276,19): error CS0246: (NETCORE_ENGINEERING_TELEMETRY=Build) The type or namespace name 'DbCommand' could not be found (are you missing a using directive or an assembly reference?)
Check failure on line 7 in src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.cs

@azure-pipelines
azure-pipelines
/ microsoft.testfx (Build Windows Debug)
src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.cs#L7

src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.cs(7,1): error IDE0005: (NETCORE_ENGINEERING_TELEMETRY=Build) Using directive is unnecessary. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0005)
Check failure on line 5 in src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Data.cs

@azure-pipelines
azure-pipelines
/ microsoft.testfx (Build Windows Debug)
src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Data.cs#L5

src\Adapter\MSTestAdapter.PlatformServices\Data\TestDataConnectionSql.Data.cs(5,1): error IDE0005: (NETCORE_ENGINEERING_TELEMETRY=Build) Using directive is unnecessary. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0005)

[Copilot]

Pull request overview

This PR refactors TestDataConnectionSql into focused partial-class modules while preserving its NETFRAMEWORK-only data connection behavior.

Changes:

• Keeps construction, factory setup, connection state, and disposal in the core file.
• Moves identifier quoting/name parsing, schema discovery, helper types/constants, and table reads into separate partial files.
• Converts TestDataConnectionSql to a partial class to support the split.

Show a summary per file

File	Description
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.cs	Retains core lifecycle and changes the class to partial.
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.Quotes.cs	Adds quote prefix/suffix and identifier quoting helpers.
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.Names.cs	Adds table/name splitting and quote-joining logic.
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.Schema.cs	Adds schema, table/view, column, and default schema helpers.
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.Data.cs	Adds table reading and column projection SQL generation.
src/Adapter/MSTestAdapter.PlatformServices/Data/TestDataConnectionSql.Helpers.cs	Adds shared provider helpers, metadata structs, and known provider constants.

Copilot's findings

• Files reviewed: 6/6 changed files
• Comments generated: 1

[Copilot]

@copilot fix the following build issues

@azure-pipelines
...

Addressed in b6ead4e.

[Copilot]

Copilot's findings

• Files reviewed: 6/6 changed files
• Comments generated: 0 new