Precompiled query/NativeAOT work

[roji]

Implement test suites: AdHocPrecompiledQueryRelationalTestBase, PrecompiledQueryRelationalTestBase, PrecompiledSqlPregenerationQueryRelationalTestBase.

[ChrisJollyAU]

I have something for this. Most just works straight out the box.

Have a couple that don't work though

The type 'NpgsqlTsQuery' is defined in an assembly that is not referenced. You must add a reference to assembly 'Npgsql, Version=8.0.3.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7'

How do you add a reference to an assembly with precompile queries?

[roji]

Initial test work done by @ChrisJollyAU in #3289 (thanks!). We still need to ensure quoting is supported (and tested) by all Npgsql-specific expression types.