Add cache bust feature

[am2222]

Hi,

I was wondering if there is any chance we can add cache bust feature to the tilejson. technically once we renew tiles in the server browsers still use the locally cached data. one workaround is to add a has of last-modified from tile metadata as a query parameter to the tilejson.tiles and it will make browser to invalidate their cache.

I need to read the source code more but I think we can add it here.
https://github.com/maptiler/tileserver-gl/blob/500a81e8b32aa83247ff3146a854eecf7059e491/src/serve_data.js#L210C5-L212C7

I can make a PR for this if that makes sense from your perspective!

[am2222]

@acalcutt does it get merged if I make a PR for it? Thanks!

[acalcutt]

You can submit a PR for review and we can see. I'm not really familiar with this so we would have to test and see if there are any comments before it got merged.

[am2222]

@acalcutt Thanks! I just created a PR for it, please let me know what are your thoughts (#1307)