Improve user verification in ajax backend passwordMail by adding an instance check for
QUI\\Users\\User before calling sendPassword method.
Remove redundant error messages in phpstan-baseline.neon associated with previously incorrect user
activation logic and unsupported comparison evaluations in Customers.php and Search.php.
Correct arguments for activate method in Customers.php from false to empty string.
Add 'users.customerId' to allowed search columns and adjust type hints for arguments in `limit` and
`setFilter` methods in Search.php to include spaces for better readability.

Related: #67