feat: Label automation workflows & old workflow cleanup

[jimblanc]

Description of changes

Introduces new workflows to manage issue label automation & cleans up a few unused workflows and ticket templates.

Summary of label life-cycle changes:

• New community-opened issues will receive pending-maintainer-response & pending-triage
• pending-maintainer-response will be removed if a maintainer comments on the ticket
• Subsequent comments from the community will re-add pending-maintainer-response
• pending-response has been renamed to pending-community-response
• Applying bug, feature-request, or question will remove the pending-triage label

The pending-maintainer-response label can still be removed manually depending on the context of the customer's most recent response.

Issue #, if available

Description of how you validated changes

Tested on fork:

• Maintainer created ticket: TEST ISSUE (Maintainer opened) jimblanc/amplify-js#6
• Community created ticket: [Test] Bug reported jimblanc/amplify-js#7

Checklist

• PR description included
• yarn test passes
• Unit Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)

Checklist for repo maintainers

• Verify E2E tests for existing workflows are working as expected or add E2E tests for newly added workflows
• New source file paths included in this PR have been added to CODEOWNERS, if appropriate

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ashika112]

Neat 👍