Allow extension key prefixes 'tt_'
Describe the task
In Version 3.6.2 from 2004-07-12 the exensions starting with 'tt' have been removed from TYPO3 and published as external extensions. So please allow those 'tt_' prefixes for all extension keys.
What does success look like, and how can we measure that?
The reservation of an extension key tt_example shall be possible.