Make Linter Extension and API public

[saintentropy]

Purpose

Expose the LinterExtensionBase as a public base class so that user can create linter extensions to create rule sets for Dynamo graphs beyond the GenerativeDesign type.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

(FILL ME IN) Brief description of the fix / enhancement. Mandatory section

Reviewers

@BogdanZavu .

FYIs

@mjkkirschner @twastvedt

[BogdanZavu]

I think there are a few more things :
internal abstract class LinterExtensionBase
internal event Action OnLinterLinkToWorkspace
internal event Action OnLinterUnlinkFromWorkspace
internal class GraphRuleEvaluationResult
internal class NodeRuleEvaluationResult
internal void OnRuleEvaluated(IRuleEvaluationResult result)
internal bool IsActive => this.linterManager?.IsExtensionActive(UniqueId) ?? false;
internal void InitializeBase(LinterManager linterManager)

[BogdanZavu]

Thinking of the minimal exposure needed for the upcoming DA check rules I think we only need internal abstract class LinterExtensionBase from the list above so let's add that and then LGTM @saintentropy

[QilongTang]

@saintentropy @BogdanZavu @twastvedt We are going to release Dynamo 2.18 soon, is this one required?

[saintentropy]

@QilongTang Yes please

[QilongTang]

@saintentropy Please cherry-pick this to RC branch as well then