feat(rule): add ACT Rule IDs to test rule objects

[rweberkaf]

Add new property actIds to axe-core rule objects and populate with ACT Rule IDs; update validation schema to permit them. Link to corresponding ACT description pages in rule-descriptions.md.

Closes issue: #2820

[straker]

Thank you for the pr. @WilcoFiers will need to look over it, but we've been super busy preparing for the 4.2 release coming in the next few weeks. I'm not sure this pr will get in before the release so it might be a bit before he can get to it.

[WilcoFiers]

@rweberkaf Just to update you on this. This PR in came in just a little too late to make it into the 4.2 release. We'll pull this in after 4.2 is released. Some time next week I imagine.

[WilcoFiers]

@rweberkaf can you merge develop back into your branch. To resolve the merge conflict, best to just rerun grunt build. It'll create a new version of the file that's conflicting now.

[rweberkaf]

All set, @WilcoFiers , thank you!

[WilcoFiers]

Thank you for the contribution @rweberkaf! It is very much appreciated.

[WilcoFiers]

And for the record, I reviewed this PR for security.