[TASK] Remove unused code in TER API and use modern APIs
The tx_ter_api class is cleaned up as follows:
- Use PSR-3 logging mechanisms instead of TYPO3_DLOG constants
- Remove reference to cObj as it is not needed at all
- Remove calls to empty protected methods as they are not needed anymore
- Remove non-existant definition for tx_ter_extensionqueue.hidden (DB field does not exist)