[Admin] Add possibility to add custom admin languages - fixes pimcore…

…#5425

[DOCS] Added missing events to list

Backport of pimcore#5401 fbda71e 2FA bypass issue

Merge pull request pimcore#5391 from pimcore/thumbnail_generate_command

[Asset] Improvements for pimcore:thumbnails:image Command: high-res, webp and media queries support

Update .travis.yml

Merge pull request pimcore#5312 from pimcore/grids_notice

Add grid helpers refactoring notice pimcore#5304

Merge pull request pimcore#5287 from pimcore/search_and_move

[Admin] DataObjects - Allow 'Search and Move' on Empty Folders

[Composer] Dependency issue with monolog-bundle - backport of pimcore…

…#5246

Coding Standards Fixer Bot

Update es.extended.json (POEditor.com)