Fix: handle error also for TMS/VectorTiles

[AlitaBernachot]

This PR adds a tile load function error handler also for VectorTileLayer/VectorTile/MVT (mapbox vector tiles) wich is used for Gprf's "TMS".

[jahow]

thank you! also for the simplification 🙏

[AlitaBernachot]

oh wait, reading again my code i have a small doubt about https://github.com/camptocamp/geospatial-sdk/pull/28/files#diff-0b30aedb7e9a5ebe8ea53b20abbb66f80186473926617a659c600b2c8ff171fbR50, the layer is not yet iniatialized at this point, but it is afterwards when tileLoadFunction is called later, it works, but is it ok to keep it as is? 🤔

[jahow]

oh wait, reading again my code i have a small doubt about https://github.com/camptocamp/geospatial-sdk/pull/28/files#diff-0b30aedb7e9a5ebe8ea53b20abbb66f80186473926617a659c600b2c8ff171fbR50, the layer is not yet iniatialized at this point, but it is afterwards when tileLoadFunction is called later, it works, but is it ok to keep it as is? 🤔

Oh sorry, I thought it was the layer model that was given. I'm not 100% sure it will work, maybe try adding a more complete unit test?

[AlitaBernachot]

Oopsy i was too fast on that one! I set the tileLoadfunction for Image to the VectorTile tileLoadFunction... this handler may need some more work.
I think i have managed to fix the issue on gn-ui side, so i probably won't need this evolution.
Sorry for this false alert. I'll try to have a look later if this is a needed feature.