Release v2.0.0-ALPHA23

Added

• [Core] Add support for unbound values in StringInput (sstok) #278
• [BC BREAK] Symfony 5 support (sstok) #285
• [BC BREAK] [Doctrine] Simplify usage and safety (sstok) #286

Changed

• Typo (smoench) #274
• Docs improvements (sstok) #277
• Add GitHub CI workflow configuration (sstok) #281
• Phpstan fixes (sstok) #282
• Clean code refactoring (sstok) #284

Fixed

• [Core] Fix failing LanguageTypeTest (sstok) #279
• [Doctrine] Fix cache storing prepend with cache (sstok) #283