Allow to uninstall (hide) Audit application
Summary:
While many Phorge applications can be uninstalled (such as Differential for pre-merge commit review), this has not been the case for Audit (post-merge commit review) since rP11861265fe94fa97e4d0563c5bdb7b8cac27282d.
In installations which do not use Audit in their workflows, exposing Audit related UI elements creates additional clutter and complexity.
Fixes T15129
Test Plan:
* Go to `/applications/view/PhabricatorAuditApplication/` and click "Uninstall"
* View an individual merged commit in Diffusion, click "Edit Commit" in the sidebar to go to `/diffusion/commit/edit/1/`, see that "Auditors" datasource is not displayed
* View an individual merged commit in Diffusion, click the "Add Action..." dropdown, see that the "Audit Action" section and its entries "Accept Commit" and "Raise Concern" are not displayed
* View an individual merged commit in Diffusion, click the "Add Action..." dropdown, see that the "Change Auditors" entry is not displayed
* Go to `/conduit/` and see that the API method "audit.query" and the entire section "audit" is not displayed
* Go to `/diffusion/commit/` and see no "Active Audits" and "Audited" searches in the left side bar
* Go to `/diffusion/commit/query/all/` and see that no "Auditors" entry is shown for each commit
* Go to `/diffusion/commit/query/all/` and see that no audit related entry is shown in the grey column on the right (if Harbormaster is not installed, there will be no grey column at all)
* Go to `/herald/edit/?content_type=commit&rule_type=global` and see that no Condition entry "Auditors" and no Condition entry "Affected packages that need audit" is displayed
* Go to `/herald/edit/?content_type=commit&rule_type=personal` and see that no "Add me as an auditor" Herald action and no "Added Auditors" Herald condition is displayed
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T15129
Differential Revision: https://we.phorge.it/D25503