Fix test failures: update version checks and fix JSON parsing with tr…

…ailing nulls

update readme and versions

codecov update

DI workflow for nuget packages order changed

check in latest enhancements functional engine for 1.6.0 not fully te…

…sted with 1762 tests

all nugets updated

Fix: Ensure only src/ projects are packable for NuGet

PROBLEM: Test and manual projects in tests/ directory were inheriting packaging properties from Directory.Build.props and could be packed unintentionally.

SOLUTION: Added IsPackable=false to all test, manual, demo, benchmark, and profiling projects in tests/ directory.

AFFECTED PROJECTS: - tests/DiagTest - tests/Manual/RefFieldDemo - tests/Manual/SingleFileTest - tests/SharpCoreDB.Benchmarks - tests/SharpCoreDB.DemoJoinsSubQ - tests/SharpCoreDB.Profiling - tests/SharpCoreDB.Provider.Sync.Tests

RESULT: Only projects in src/ directory will be packable as NuGet packages.

fix(ci): add Performance trait to ColumnStoreTests to exclude timing-…

…sensitive tests from CI runners

commit new readme files

updated nugets inline with release versions