PHPStan prepare exceptions (#6037)

Take advantage of
https://phpstan.org/blog/bring-your-exceptions-under-control

Minimum changes to pass `tooWideThrowType` and `implicitThrows`.

Revert some mistakes from:
https://github.com/FreshRSS/FreshRSS/pull/5504
Preparation needed before new PRs of the same type:
https://github.com/FreshRSS/FreshRSS/pull/5962

Fix several wrong PHPDocs and catches:

> Method ... has ...Exception in PHPDoc @throws tag but it's not thrown.

> Dead catch - ...Exception is never thrown in the try block.

app/Controllers/authController.php

@@ -65,7 +65,6 @@ class FreshRSS_auth_Controller extends FreshRSS_ActionController {
 	 *
 	 * It forwards to the correct login page (form) or main page if
 	 * the user is already connected.
-	 * @throws Minz_ConfigurationParamException
 	 */
 	public function loginAction(): void {
 		if (FreshRSS_Auth::hasAccess() && Minz_Request::paramString('u') === '') {