Enables single-level Include operator for in-memory.
Merge branch 'inc-latest' into dev
Adding WithCurrentCulture extension method

Part of #374
Enhanced unit tests for code generators to compile the generated code, load, instantiate, execute, and re-generate from compiled result.
Fixed a few issues discovered while running the enhanced tests.
Changing ConfigureAwait(false) to WithCurrentCulture()

Part of #374
Adding some basic tests for DatabaseErrorPageMiddleware