MM-56082 Add PreferencesHaveChanged plugin hook (#25659)

* Add interface for PreferencesHaveChanged hook

* Add context to preference-related methods of App

* Implement PreferencesHaveChanged

* Re-add missing "fmt" import

* Update minimum server version for the new hook

* Remove pointers to be consistent with other preference APIs

server/channels/app/plugin_api.go

@@ -271,15 +271,15 @@ func (api *PluginAPI) GetUsersInTeam(teamID string, page int, perPage int) ([]*m
 }
 
 func (api *PluginAPI) GetPreferencesForUser(userID string) ([]model.Preference, *model.AppError) {
-	return api.app.GetPreferencesForUser(userID)
+	return api.app.GetPreferencesForUser(api.ctx, userID)
 }
 
 func (api *PluginAPI) UpdatePreferencesForUser(userID string, preferences []model.Preference) *model.AppError {
-	return api.app.UpdatePreferences(userID, preferences)
+	return api.app.UpdatePreferences(api.ctx, userID, preferences)
 }
 
 func (api *PluginAPI) DeletePreferencesForUser(userID string, preferences []model.Preference) *model.AppError {
-	return api.app.DeletePreferences(userID, preferences)
+	return api.app.DeletePreferences(api.ctx, userID, preferences)
 }
 
 func (api *PluginAPI) GetSession(sessionID string) (*model.Session, *model.AppError) {