Add show_dsc_schema() MCP function

[SteveL-MSFT]

PR Summary

• Add new show_dsc_schema tool that is equivalent to dsc schema command
• Added some missing schemas to list that can be returned
• Fixed how schemas are returned due to change in rcmp crate

[Copilot]

Pull request overview

Adds a new show_dsc_schema MCP tool that mirrors the existing dsc schema CLI command, expanding SchemaType to cover several previously-missing schemas and bumping the rmcp dependency so that schema results can be returned via the updated schemars::Schema API.

Changes:

• New show_dsc_schema MCP tool, registered in mcp/mod.rs and mcp_server.rs, with a corresponding integration test.
• SchemaType gains AdaptedDscResourceManifest, ConfigurationExportResult, ResourceGetResult, ResourceSetResult, ResourceTestResult (plus Deserialize/JsonSchema derives), with matching arms in util::get_schema.
• Bumps rmcp from 1.5.0 to 1.7.0 and adjusts show_dsc_resource to declare an explicit nullable-object schema for its Option<Value> field.

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
dsc/src/mcp/show_dsc_schema.rs	New MCP tool exposing get_schema via ShowSchemaRequest/ShowSchemaResponse.
dsc/src/mcp/mod.rs	Declares the new show_dsc_schema module.
dsc/src/mcp/mcp_server.rs	Adds the new tool's router to the combined ToolRouter.
dsc/src/mcp/show_dsc_resource.rs	Adds explicit nullable_json_object_schema for the schema: Option<Value> field (needed for rmcp 1.7).
dsc/src/args.rs	Adds new SchemaType variants and derives Deserialize + JsonSchema.
dsc/src/util.rs	Maps the new SchemaType variants to schema_for! calls.
dsc/tests/dsc_mcp.tests.ps1	Registers show_dsc_schema in the tool inventory test and adds a smoke test.
Cargo.toml / Cargo.lock	Bumps rmcp to 1.7.0.