Remove dead code

[MitchRazga]

Contributes to #383

I created a tool to identifty unreferenced members in a solution.
It found these and I removed them manually.

• AttributeDataExtensions.GetNamespaces
• IEventSymbolExtensions.GetNamespaces
• IMethodSymbolExtensions.GetNamespaces
• IPropertySymbolExtensions.GetNamespaces
• ObjectExtensions.FormatValue
• SyntaxNodeExtensions.HasUsing

I also removed their corresponding tests since they are no longer needed.

• AttributeDataExtensionsTests.GetNamespaces
• IEventSymbolGetNamespacesExtensionsTests
• IMethodSymbolExtensionsGetNamespacesTests
• ObjectExtensionsTests.FormatValue
• ObjectExtensionsTests.FormatEnumValue
• ObjectExtensionsTests.FormatEnumValueWhenValueIsIncorrect
• ObjectExtensionsTests.FormatNullValue
• ObjectExtensionsTests.FormatCollectionValue

All tests passed.
Rocks.CodeGenerationTest Generator testing complete.

	Total assembly count is 121
	Total discovered type count is 18051

[MitchRazga]

There may be more. Will scan again once #394 is finished.

[JasonBock]

I was just about to say, let's keep this PR open until #394 is done :)

[JasonBock]

Hey @MitchRazga, #394 is now committed, do you think you'll be able to resolve merge conflict and maybe find any other sources of dead code before I release 10.0.0? I don't have an exact date for this, but I'm guessing it'll be sometime near the end of November.

[MitchRazga]

Hey @MitchRazga, #394 is now committed, do you think you'll be able to resolve merge conflict and maybe find any other sources of dead code before I release 10.0.0? I don't have an exact date for this, but I'm guessing it'll be sometime near the end of November.

I'll rebase on main and re-run the tool tomorrow 😄

[MitchRazga]

Done.
Didn't find anything else on the rerun. There are a few minor ones like:
Rocks.Analysis.Models.EquatableArray.AsEquatableArray<T>(System.Collections.Immutable.ImmutableArray<T>)
Rocks.Analysis.Models.EquatableArray<T>.ToArray()
but have left those in since that class gets copy-pasted occassionally.

1345 Tests Passed.
Generator testing complete.

Total assembly count is 122
Total discovered type count is 20775

[JasonBock]

LGTM @MitchRazga!