Allows comments in prompt templates

[JonasHelming]

This should be reviewed first: #14465

fixed #14469

What it does

Allows comments in prompt templates

• Comments must start in the first line only, but can then be multile lines
• Comments are {{!-- comment --}}

How to test

There are automated tests.

Manual test:
Add comments and observe no effect on:

• LLM requests
• Variable detection in the AI configuration view

Check comments are highlighted correctly in the prompt editor:

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[planger]

Nice, works pretty well! I don't approve it yet, because it is based on another PR that hasn't been approved yet and I want to avoid accidentally merging the other commit.

Code looks good! I just have a few general thoughts that me might want to address:

Line 7 above:
The syntax highlighting shows the content of line 7 as comment, whereas in reality it isn't. This might be confusing.

Line 6 above:
It doesn't show the comment-like string as a comment, however, due to the similar begin and end delimiters to variables, it highlights this false comment as a variable. This again might be a bit confusing. Maybe it'd be better to choose a different sequence of characters for comments, to avoid this overlap and false highlighting.

[JonasHelming]

I will check this once #14465 is done, as it needs to be tested in combination

[JonasHelming]

Line 6 above:
It doesn't show the comment-like string as a comment, however, due to the similar begin and end delimiters to variables, it highlights this false comment as a variable. This again might be a bit confusing. Maybe it'd be better to choose a different sequence of characters for comments, to avoid this overlap and false highlighting.

This is actually expected. This was a trade off. {{!-- is a very common pattern in template engines. Also we take less characters away for regular usage in prompts. So if {{!-- occurs somewhere not in the first line, it is indeed treated as a variable.

The other issue should be fixed now

[planger]

Thanks, looks good to me! 👍