[New] Introduce a plugin-wide setting for custom components.

[pcorpet]

For #174

This is an early version of the change I want to introduce: there are still some rules that I haven't updated.
Can you start a review on the API and the implementation to see if I should finish it please?

[codecov]

Codecov Report

Merging #844 (64dcac6) into main (1826628) will increase coverage by 0.03%.
The diff coverage is 99.76%.

@@            Coverage Diff             @@
##             main     #844      +/-   ##
==========================================
+ Coverage   99.22%   99.25%   +0.03%     
==========================================
  Files          98       99       +1     
  Lines        1417     1476      +59     
  Branches      479      482       +3     
==========================================
+ Hits         1406     1465      +59     
  Misses         11       11              

Impacted Files	Coverage Δ
__tests__/__util__/parserOptionsMapper.js	100.00% <ø> (ø)
src/rules/interactive-supports-focus.js	97.14% <96.66%> (+0.17%)	⬆️
__tests__/__util__/ruleOptionsMapperFactory.js	100.00% <100.00%> (ø)
src/rules/accessible-emoji.js	100.00% <100.00%> (ø)
src/rules/alt-text.js	100.00% <100.00%> (ø)
src/rules/anchor-has-content.js	100.00% <100.00%> (ø)
src/rules/anchor-is-valid.js	100.00% <100.00%> (ø)
src/rules/aria-activedescendant-has-tabindex.js	100.00% <100.00%> (ø)
src/rules/aria-role.js	100.00% <100.00%> (ø)
src/rules/aria-unsupported-elements.js	100.00% <100.00%> (ø)
... and 26 more

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[jessebeach]

Love it, thank you for starting this.

I have a 10 week old at home and he's been a bit of a drag on time and energy for Open Source :) I'll try to find time to review, but if I'm a little slow, it's cause I'm changing diapers ;p

[ljharb]

Looks great!

[pcorpet]

I'm done updating every existing rule and helper function that was using the raw elemType function and I've added test cases for all of them I believe.

[joshuajaco]

We also need something like this, because control-has-associated-label's controlComponents option currently does not allow globs, unlike label-has-associated-control. I would greatly appreciate this being merged soon.

[ljharb]

Looks great!