DPUB-ARIA and DPUB-AAM 1.1 Recommendations

DPUB-ARIA and DPUB-AAM 1.1 Proposed Recommendation

Add ariaBrailleLabel and ariaBrailleRoleDescription ARIAMixin reflect…

…ions (#2039)

This adds the following string reflections to ARIAMixin:

- `ariaBrailleLabel` -> `aria-braillelabel`
- `ariaBrailleRoleDescription` -> `aria-brailleroledescription`

These reflections are already implemented in Chromium (see [here](https://source.chromium.org/chromium/chromium/src/+/main:out/fuchsia-Debug/gen/third_party/blink/renderer/bindings/modules/v8/v8_element.cc;l=1201;drc=168fe20dbf8ab7e47e36db5e528ec3c95c2f8af0) and [here](https://source.chromium.org/chromium/chromium/src/+/main:out/fuchsia-Debug/gen/third_party/blink/renderer/bindings/modules/v8/v8_element.cc;l=1228;drc=168fe20dbf8ab7e47e36db5e528ec3c95c2f8af0)), but not yet in WebKit or Firefox.

The purpose of this PR is to align with the de-facto behavior of Chromium. I don't see a strong reason for the spec not to include these particular reflections. (If there is one, please let me know!)

See also: #923

# PR tracking
Check these when the relevant issue or PR has been made, OR after you have confirmed the
related change is not necessary (add N/A). Leave unchecked if you are unsure. Read the
[Process Document](https://github.com/w3c/aria/wiki/ARIA-WG-Process-Document/_edit) or
[Test Overview](https://github.com/w3c/aria/wiki/ARIA-Test-Overview) for more information.

* [x] Related Core AAM Issue/PR: does not apply
* [x] Related AccName Issue/PR:  does not apply
* [x] Related APG Issue/PR: does not apply
* [x] Any other dependent changes? no.

# Implementation tracking

* [x] "author MUST" tests:  does not apply
* [x] "user agent MUST" tests: web-platform-tests/wpt#42751
* [x] Browser implementations (link to issue or when done, link to commit):
   * WebKit: No (https://bugs.webkit.org/show_bug.cgi?id=263663)
   * Gecko: No (https://bugzilla.mozilla.org/show_bug.cgi?id=1861201)
   * Blink: [here](https://source.chromium.org/chromium/chromium/src/+/main:out/fuchsia-Debug/gen/third_party/blink/renderer/bindings/modules/v8/v8_element.cc;l=1201;drc=168fe20dbf8ab7e47e36db5e528ec3c95c2f8af0) and [here](https://source.chromium.org/chromium/chromium/src/+/main:out/fuchsia-Debug/gen/third_party/blink/renderer/bindings/modules/v8/v8_element.cc;l=1228;drc=168fe20dbf8ab7e47e36db5e528ec3c95c2f8af0)
* [x] Does this need AT implementations? no.

Working Draft version 1.2.2

Tristate value type: default value should be "undefined" (closes #773) (

#774)

Merge branch 'Rec_2017_normative_fix' into Rec_2017

put canonical term first in list in data-lt

because friggin respec changed its behaviour again

Merge remote-tracking branch 'refs/remotes/origin/master' into Core-A…

…AM_CR

update CR date

ARIA 1.1 CR candidate (first)