Update some APIs

- Rename DiscussionSearchWillBePerformed to ConfigureDiscussionSearch, same with users
- Add some handy methods

src/Core/Search/Discussion/DiscussionSearcher.php

@@ -16,7 +16,7 @@ use Flarum\Core\Search\SearchCriteria;
 use Flarum\Core\Search\GambitManager;
 use Flarum\Core\Repository\DiscussionRepository;
 use Flarum\Core\Repository\PostRepository;
-use Flarum\Event\DiscussionSearchWillBePerformed;
+use Flarum\Event\ConfigureDiscussionSearch;
 use Flarum\Core\Search\SearchResults;
 use Illuminate\Database\Eloquent\Collection;
 
@@ -82,7 +82,7 @@ class DiscussionSearcher
         $this->applyLimit($search, $limit + 1);
 
         // TODO: inject dispatcher
-        event(new DiscussionSearchWillBePerformed($search, $criteria));
+        event(new ConfigureDiscussionSearch($search, $criteria));
 
         // Execute the search query and retrieve the results. We get one more
         // results than the user asked for, so that we can say if there are more

src/Core/Search/User/UserSearcher.php

@@ -15,7 +15,7 @@ use Flarum\Core\Search\GambitManager;
 use Flarum\Core\Search\SearchCriteria;
 use Flarum\Core\Search\SearchResults;
 use Flarum\Core\Repository\UserRepository;
-use Flarum\Event\UserSearchWillBePerformed;
+use Flarum\Event\ConfigureUserSearch;
 
 /**
  * Takes a UserSearchCriteria object, performs a search using gambits,
@@ -68,7 +68,7 @@ class UserSearcher
         $this->applyOffset($search, $offset);
         $this->applyLimit($search, $limit + 1);
 
-        event(new UserSearchWillBePerformed($search, $criteria));
+        event(new ConfigureUserSearch($search, $criteria));
 
         // Execute the search query and retrieve the results. We get one more
         // results than the user asked for, so that we can say if there are more