Add getQueryApplicationClass() to *TransactionQuery.php classes
Summary:
Add `getQueryApplicationClass()` to all `*TransactionQuery.php` classes similar to other `*Query.php` classes having the same function, and make the parent function in `PhabricatorApplicationTransactionQuery.php` abstract.
In the future, this will enable excluding transaction query results based on their underlying application (for example if an application has been uninstalled) to mitigate the problem of overheated search results. See https://we.phorge.it/T15642 for context.
The only callers of `getQueryApplicationClass()` are in `src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php` and `src/applications/policy/__tests__/PhabricatorPolicyTestCase.php`.
See T15642
Test Plan:
Patch changes only one existing code place, thus check if related pages still work as expected:
* Go to http://phorge.localhost/feed/
* Go to http://phorge.localhost/feed/transactions/
* On http://phorge.localhost/feed/transactions/ , click `Edit Query` and set `Object Types` to `Application` etc.
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T15642
Differential Revision: https://we.phorge.it/D25500