[feat] add more logs, handle case of existing folder, not being a file

[refactor] always re-create the folder using WRITE_TMP_ON_DISK env

[debug] add more debug logs

[feat] try handling missing folder at WRITE_TMP_ON_DISK env

[feat] prepare vis_output folder within /tmp

[debug] show more details in case of exceptions, again

[debug] show more details in case of exceptions

[feat] add option to donwload files written in custom path folder

[feat] take advantage of re-usable image embeddings in SAM model

[chore] update dependencies version, both for backend and static frontend, bump to version 1.2.2

[refactor] move core instance segmentation (segment anything) functionality to samgis_core, bump to version 1.2.0

[test] add fastapi app test cases

[feat] (backend) add nextzen terrain xyz provider as DEM raster source, make sam predictions with RGB image made with normalized slope, elevation and curvature as channels

[feat] add working static frontend