Slash is not possible for an identifier

[PKuhlmay]

https://docs.typo3.org/p/contentblocks/content-blocks/main/en-us/YamlReference/Basics/Index.html

When you use basics, you use a slash inside the identifier, this is not allowed at the moment. The regex needs to be adjusted.

[nhovratov]

I would just remove the regex here, as the string type is enough for validation.