* Complete PHPStan Level 6
Fix https://github.com/FreshRSS/FreshRSS/issues/4112
And initiate PHPStan Level 7
* PHPStan Level 6 for tests
* Use phpstan/phpstan-phpunit
* Update to PHPStan version 1.10
* Fix mixed bug
* Fix mixed return bug
* Fix paginator bug
* Fix FreshRSS_UserConfiguration
* A couple more Minz_Configuration bug fixes
* A few trivial PHPStan Level 7 fixes
* A few more simple PHPStan Level 7
* More files passing PHPStan Level 7
Add interface to replace removed class from https://github.com/FreshRSS/FreshRSS/pull/5251
* A few more PHPStan Level 7 preparations
* A few last details
* - Add test and type hinting
- pass PhpStan Level 9
* fix dump
* fix style
* fix visibility
* fix style
* add test
* add test
* add test
* add test
* add test
* Simplify
* cleaning after test
* remove space
* fix style
* use specific log file for test
* Remarque's from Alkarex
* A few more details
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Co-authored-by: Luc <sanchezluc+freshrss@gmail.com>
Co-authored-by: Alexandre Alapetite <alexandre@alapetite.fr>