Make admin list filters behave more consistently.

Problem/Motivation

We have several filterable admin listings in Drupal core, e.g. the modules page.
The behaviour of these is inconsistent in various ways:

• The way they are labelled
• Some have feedback for screen reader users, others don't.

Filterable lists in core:

• Modules install
• Modules uninstall
• Simpletest - Drupal.behaviors.simpletestTableFilterByText
• Blocks - Drupal.behaviors.blockFilterByText
• Views main listing - Drupal.behaviors.viewTableFilterByText
• Views handlers ("add field" dialog, etc)
• Layout builder blocks - in progress, see #2998862: The Layout Builder block listing should be filterable →

.

Proposed resolution

Add announcements to filters which don't have them yet.

• Views main listing - 🐛 Provide screen-reader feedback when Views UI filterable options are updated Needs work
• Views UI - dialogs for adding handlers like fields, sorts, etc. 🐛 Provide screen reader feedback when Views List is filtered by name or description Needs work
• Simpletest - #2897430: Provide screen-reader feedback when filtering by test name. →
• Others?

Consistent language in filter field - label, description. 🐛 Admin list filter fields are inconsistently labelled. Active
Consistent language in Drupal.announce() messages.
Correct pluralization of result count in Drupal.announce().
Drupal.announce() should also announce that all items are shown, after a user clears the filter field (i.e. no items are hidden).
Search by machine name and human-readable name where appropriate.
Display machine name in any lists that allow filtering on it.

Creating a reusable component for this? To remove the individual implementations we have so far. NEEDS CHILD ISSUE.

• Views main listing has one filter which controls 2 lists.
• Views handlers have 2 inputs that both control the same list (a text field and a select).

Add behaviour to visually highlight the matched strings in the result list?

Add a developer handbook page about all this, with all the advice they need to follow.

Remaining tasks

See related/child issues.
Anything else?

User interface changes

Improvements to filterable lists, for consistency and accessibility.

API changes

TBD - possibility of introducing a re-usable filter component.

Data model changes

TBD - none?