refactor(aria/tabs): clean up tab selection and linking to panels, add direct template ref

[adolgachev]

Refactors Tabs pattern to simplify how tabs are associated with their tab panels, as well as other dependent code.

This is a revision of the previous approach which swapped to use contentChildren and template references only. Instead there are 3 commits with layered changes:

1. Clean up and re-factoring to move the value matching of Tab and TabPanel to the directive and remove extra synching of selection and linked state in favor of a more direct approach.
2. Add in template references for linking which can be used in many cases when defining tabs declaratively and removes need to use values and ensure they match. The value matching is preserved. Examples updated. If stop here, will need to add validation as both value and panelRef are optional.
3. Remove value matching in favor of matching Tab with its TabPanel using the panel (generated or set) Id. This moves back to a single required panel reference field. One issue is that I'm not fond of selectedTab being set with the panel id (although can also add set via template ref to the tab).

[github-actions]

Deployed dev-app for edf03c8 to: https://ng-dev-previews-comp--pr-angular-components-32859-dev-pxtvzh2b.web.app

Note: As new commits are pushed to this pull request, this link is updated after the preview is rebuilt.

[github-actions]

Deployed docs-preview for edf03c8 to: https://ng-dev-previews-comp--pr-angular-components-32859-docs-58cy5tjn.web.app

Note: As new commits are pushed to this pull request, this link is updated after the preview is rebuilt.

[ok7sai]

We should put this change on hold for two main reasons

• Static Id assignment is discouraged internally.
• Unlike Accordion that a trigger-panel pair are strongly coupled in the document, tabs and panels are two separated groups so the template reference passing can easily fail due to the scoping issue. A common use case we've seen is the tablist gets wrapped into a standalone component.

value input might no be the cleanest implementation, but I also don't see a big drawback of it.