Fix trimming warnings in Microsoft.Data.Sqlite

[ajcvickers]

Fixes #29725

There were two types of issue:

• In SqliteConnection, the linker was unable to determine the type returned by the GetType call. Fixed by explicitly specifying the type.
• In SqliteDataReader, GetFieldType on the base has been annotated with DynamicallyAccessedMembers, which needed to be flowed through to called methods.

Tested with code from Nanorm

After fixes:

PS C:\local\code\TrimTest\TrimTest> dotnet publish -f net8.0 -r win10-x64 --self-contained -v m --nologo -o pub
  Determining projects to restore...
  Restored C:\local\code\TrimTest\TrimTest\TrimTest.csproj (in 283 ms).
  Restored C:\local\code\TrimTest\Nanorm.Sqlite\Nanorm.Sqlite.csproj (in 283 ms).
  Restored C:\local\code\TrimTest\Nanorm\Nanorm.csproj (in 283 ms).
C:\Program Files\dotnet\sdk\8.0.100-preview.3.23178.7\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.RuntimeIdentifierInference.targets(287,5): message NETSDK1057: You are using a preview version of .NET. See: https://aka.ms/dotnet-support-policy [C:\local\code\TrimTest\TrimTest\TrimTest.csproj]
  Nanorm -> C:\local\code\TrimTest\Nanorm\bin\Release\net8.0\Nanorm.dll
  Nanorm.Sqlite -> C:\local\code\TrimTest\Nanorm.Sqlite\bin\Release\net8.0\Nanorm.Sqlite.dll
  TrimTest -> C:\local\code\TrimTest\TrimTest\bin\Release\net8.0\win10-x64\TrimTest.dll
  Generating native code
  TrimTest -> C:\local\code\TrimTest\TrimTest\pub\