feat: add validator run event to allow plugins to perform custom validation

[RebeccaStevens]

fix #2183

[Gerrit0]

I don't think I want the validator to be a separate thing - it's not nearly complicated enough to deserve that... I'd rather just add the validate event to ApplicationEvents and emit it on the application, then if any validator logs or listener to that method logs an error, TypeDoc will exit with the ValidationError exit code.

If it does deserve pulling out into its own class someday - I'd still want to avoid the component and emit that event from the application I think... I'm not convinced that there's value for plugins in seeing a new class.

[RebeccaStevens]

@Gerrit0 I've reworked this PR to address those issues :)

[RebeccaStevens]

When working on my plugin that relies on this PR, reflection.comment.getTags("@param") always return an empty array. I'm not having this issue with any other tags. Am I missing something for this tag or is this a bug?

[Gerrit0]

I think validateProject might be better - it immediately implies that the callback will be passed a project, thoughts?

[RebeccaStevens]

So ApplicationEvents.VALIDATE_PROJECT?

[Gerrit0]

Yep, and validateProject for the string, otherwise lgtm

[RebeccaStevens]

That's all set up :)

[Gerrit0]

Thanks! Should release today.

[Gerrit0]

When working on my plugin that relies on this PR, reflection.comment.getTags("@param") always return an empty array. I'm not having this issue with any other tags. Am I missing something for this tag or is this a bug?

Just realized I forgot to answer this -- @param tags are moved to the ParameterReflection instances, so you generally shouldn't have any @param tags, your plugin should probably check that signatureReflection.parameters all have comments.