editorial: refactor aria.js (#2408)

Part of #2230

Partially moved from w3c/aria-common#106 at [caf8e9e](w3c/aria-common@caf8e9e)

From the original PR:

Much work to be done.

* [x] add a very simple test
  * `test.sh` runs respec on ARIA before/after applying aria.js changes and diffs the two results
* rough goals 
  * clarify (e.g., switch to const/let, replace reused variable names with unique ones)
  * simplify (e.g., loops over querySelectorAll, use sets instead of filtering)
  * revise HTML string creation
  * extract loops
* steps
  * [x] pdef, sdef loop
  * [x] generating HTML for indices of (global) states&properties as well as role=roletype
  * [x] rdef loop
  * [x] roleInfo loop
  * [x] propList loop
  * [x] generate HTML for role-related indices, sub-Roles
  * [x] clean-up
* continuation
  * [x] rewrite subRoles code

Co-authored-by: pkra <[email protected]>

Author: pkra