feat: Optional imports

[guillemc23]

Added optional imports, so that the package can be imported in multiple ways without the need to pull all dependencies.

FastSAM is not working because the versions pinned on the package are too old and are not properly loading the model after torch>2.6.0, I will take a look at that package. I believe we should pin all required versions in this package as well to prevent these kind of errors in the future.

[giswqs]

@guillemc23 Many thanks for the PR.

One minor change: please revert the hardcoded version change 0.13.0, which will be updated automatically with bumpversion when making a new release.

[guillemc23]

@giswqs okay! I wasn't sure what to do with it, I'll put it back to how it was.

I reverted the version both in the pyproject.toml and in __init__.py

[guillemc23]

Thank you @giswqs!
I believe that in order to make it work for python 3.13+ we would need to fix some issues on how Fast SAM loads the model, since it relies on torch 2.6 and they changed some things on how to load the weights of the model 😄

Also... we might want to add segment-geospatial[all] to other projects that require this package, like geoai