Stop applying filter updates to developer tools panel

Background / User story

We're currently using Core's defaultMatcher.match() function to update existing records in the developer tools panel in response to filter changes (e.g. filter got removed). This functionality is not going to be available to us after #972 (closed). Furthermore, the records shouldn't show filters that could've matched but filters that did match, so updating existing records probably doesn't make sense anyway.

Therefore we should stop updating existing records in the developer tools panel.

What to change

• Design: N/A
• Research: N/A
• Spec: eyeo/specs/spec!391
• Legal: TBD
• Development: In developer tools panel:
  • Stop updating existing records.
  • Restore visual feedback for action buttons.
  • If an existing request is encountered again, but with a different matching filter, a new record should be added, rather than an existing one updated. (we stopped replacing filters on existing records in #909 (closed))

Hints for testers

• The developer tools panel no longer updates in response to filter changes elsewhere in the extension.
• We don't know whether a filter actually matches any of the requests shown in the developer tools panel, so what we do is:
  • Add filter to one row, even if it could apply to some other row as well.
  • Remove filter from one or more rows.
• Removing an allowlisting filter that was added while the developer tools panel is open should show the blocking filter that was there before.
• The footer remains visible, even after undoing all the changes since the opening of the developer tools panel (i.e. removing all allowlisting filters that the user added).

Hints for translators

N/A