Enable exclusion of specified dates from date ranges

[Nate-Wessel]

This will allow the app to optionally accept a set of dates to exclude from the aggregations per date range.

Quite a few little features had to be modified to enable this without creating any reversions on other features:

• daysInRange calculations
• an additional URI GET parameter + query logic
• cache/store retrieved results in a map keyed by URI (to break cache if URI changes)
• new editing controls on the DateRange factors
• consideration of these new params in reconstruction from URIs in a file
• add asterisk in DateRange name as necessary with corresponding notes in the output

[Nate-Wessel]

@gabrielwol, I'm still doing work on the frontend of the app, but the part I'd like you to review (please and thanks!) should be stable now.

Please have a look if you would at just the changed python files in the backend/ directory.

The changes there enable a new optional GET argument like

http://localhost:8072/aggregate-travel-times/30415357/30415343/2/5/2026-03-02/2026-03-09/true/1234567?excludeDates=2026-03-04

http://localhost:8072/aggregate-travel-times/30415357/30415343/2/5/2026-03-02/2026-03-09/true/1234567?excludeDates=2026-03-04,2026-03-05

etc

[gabrielwol]

Looks good to me!

[aharpalaniTO]

Looks good. Will approve and merge. Would consider including excluded dates in its own field rather than in the notes field of the output file.