V 0.2.0-beta - Maintenance and compatibility

[UPD] Make extension available for TYPO3 10.x
[UPD] Migrate TS condition syntax, to Symfony expression language
[UPD] Migrate namespace of fluid abstract view helper
[UPD] Removed deprecated keys in ext_emconf.php
[UPD] Migrate TS file endings from .txt to .typoscript