ProhibitedInitialCharacterCheck should cover whitespace #14425
Description
Describe the problem
#14420 will start to strip leading/trailing whitespace from glossary entries. There should be a warning to the user that these strings are problematic.
Describe the solution you would like
Extending ProhibitedInitialCharacterCheck to cover this seems like the best approach. The documentation needs to be updated as well to cover whitespace in addition to CSV problematic characters.
Describe alternatives you have considered
No response
Screenshots
No response