Add quotemark type validation to allow early return (#4310)

[isabelleweber]

PR checklist

• Addresses an existing issue: fixes quotemark: Invalid regular expression: /\\)/: Unmatched ')' #4310
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Add quotemark type validation to allow early return if not one of `, ' or ".

Before:

When linting something like (a')...

SyntaxError: Invalid regular expression: /\\)/: Unmatched ')'

After:

No error

CHANGELOG.md entry:

[bugfix] additional quotemark validation

[palantirtech]

Thanks for your interest in palantir/tslint, @isabelleweber! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[JoshuaKGoldberg]

Functionality looks great - just a style comment and a test fixup.

[JoshuaKGoldberg]

👋 @isabelleweber just a heads up - I merged in master and resolved the test feedback. This'll be available in the next TSLint release!