Search: Add altitude range filter

[Gilbert32]

This pull request adds 2 search parameters, maxalt (Maximum Altitude inclusive) and minalt (Minimum Altitude inclusive).

It uses the column photos.photo_altitude to filter photos based on the specified query.
I have added the 2 parameters and basic tests based on my need, however given I don't have extensive knowledge in the photoprism source code, and go, There's the possibility I might have missed to implement it in some place in the source code.
I also added basic tests and they passed.

Acceptance Criteria:

• Features and enhancements must be fully implemented so that they can be released at any time without additional work
• Automated unit and/or acceptance tests are mandatory to ensure the changes work as expected and to reduce repetitive manual work
• Frontend components must be responsive to work and look properly on phones, tablets, and desktop computers; you must have tested them on all major browsers and different devices
• Documentation and translation updates should be provided if needed
• In case you submit database-related changes, they must be tested and compatible with SQLite 3 and MariaDB 10.5.12+

[CLAassistant]

All committers have signed the CLA.

[Gilbert32]

I have added a docs commit on my fork of photoprism-docs repository, however i'm not sure how to proceed. Should I create a PR for that if this PR was merged?

photoprism/photoprism-docs@master...Gilbert32:photoprism-docs:feature/filter_altitude

[lastzero]

Thank you! I think it makes sense to implement this in a similar way as I've just added this:

• Search: Add filters for ISO number, focal length, and aperture range #3818

[Gilbert32]

Awesome! I will adjust my code as soon as I have free time. Until then, I'm marking the issue as not fully implemented.

[Gilbert32]

I've updated the PR, now the code uses IntRange instead of separate min and max filters.

[lastzero]

@Gilbert32 I'll merge this now, but may need to change a few details:

• From what I know, the altitude can be negative.
• The filter docs should mention that it has to be specified in meters (m).

Thank you for your contribution! 🥇