More descriptive errors for printing page rage

[JasonGrace2282]

Topic of discussion

The page range option on the Ion printing page does not clearly describe the possible ways to represent the range.
For example, it might be intuitive for some people that to get the first 3 pages the page range might be 0-3, but pages
aren't zero indexed. Furthuremore, Ion only gives the vague error message of an invalid page range, which doesn't tell the user if it was a parsing issue, or an out of bounds issue, or something else.

Proposed options/solutions

Rewrite check_page_range

ion/intranet/apps/printing/views.py

Line 244 in 8cb7791

def check_page_range(page_range: str, max_pages: int) -> Optional[int]:

to return more descriptive errors (instead of returning None), and maybe add a help_text for the page range option.

Whatever behavior is added/changed should also be tested thoroughly.

Personal opinion (if applicable)

This is probably a good first issue for contributors.

It also might be worth considering making the check_page_range function a form field validator and/or overriding Form.clean - see https://docs.djangoproject.com/en/4.2/ref/forms/validation/