script/ptl-tool: map supported PR labels to Redmine QA tags

script/ptl-tool: map supported PR labels to Redmine QA tags

Introduce a supported whitelist of component tags (e.g., rgw, cephfs,
rbd, cephadm) and automatically extract matching labels from the queued
GitHub pull requests during integration branch builds.

When building or updating a Redmine QA tracking ticket:
* Append matching component tags directly to each PR line in the ticket
  description (e.g., `(tags: rgw, cephfs)`).
* Populate the `tag_list` attribute on the Redmine issue to seamlessly
  integrate with the RedmineUP Tags plugin.
* When updating an existing QA ticket, preserve any pre-existing tags
  already attached to the issue and merge them with the active PR tags.

Signed-off-by: Patrick Donnelly <pdonnell@ibm.com>