PHPStan level 5 (#4110)

* Fix most PHPDocs errors
Contributes to https://github.com/FreshRSS/FreshRSS/issues/4103
https://phpstan.org/writing-php-code/phpdoc-types

* Avoid func_get_args
Use variadic syntax instead https://php.net/manual/functions.arguments#functions.variable-arg-list
And avoid dynamic functions names when possible to more easily identify calls and unused functions.
Contributes to https://github.com/FreshRSS/FreshRSS/issues/4103

* PHPStan level 3

* PHPStand level 4

* Update default to PHPStan level 4

* Towards level 5

* Fix level 4 regression

* Towards level 5

* Pass PHPStan level 5

* Towards level 6

* Remove erronenous regression from changelog
https://github.com/FreshRSS/FreshRSS/pull/4116

app/Models/UserQuery.php

@@ -22,7 +22,7 @@ class FreshRSS_UserQuery {
 	private $tag_dao;
 
 	/**
-	 * @param array $query
+	 * @param array<string,string> $query
 	 * @param FreshRSS_Searchable $feed_dao
 	 * @param FreshRSS_Searchable $category_dao
 	 */
@@ -55,7 +55,7 @@ class FreshRSS_UserQuery {
 	/**
 	 * Convert the current object to an array.
 	 *
-	 * @return array
+	 * @return array<string,string>
 	 */
 	public function toArray() {
 		return array_filter(array(