[D8][UX] Add a "Placeholder" input field to Views Exposed Filters to allow HTML5 Placeholder

Description of the need Need the ability to add placeholders to views exposed filters.

Proposed solution

Currently the only option for an exposed filter is to add a label for information. Sometimes it looks better to remove the label and place it inside the text form field using a placeholder. Other times, the placeholder text gives a better idea of what the user needs to type or what the form is for.

Is there a Drupal or Backdrop contributed module that accomplishes this?

This was added to Drupal views core in 8.x: https://www.drupal.org/node/2935063

This is an OK workaround: https://github.com/sbgraphicdesign/form_placeholder

Additional information

See Drupal issue mentioned above for screenshot examples

Similar but unrelated issue: https://github.com/backdrop/backdrop-issues/issues/3561

Draft of feature description for Press Release (1 paragraph at most)

Backdrop now includes the ability to add placeholders to Views Exposed Filters! Instead of relying on those ugly labels, you can move them into the input field of your exposed filters or, tell people what you want them to type.

Related Request https://github.com/backdrop/backdrop-issues/issues/4956