fix: restore the ee_extra dependency

[12rambau]

Now that the ee_extra package received an update it is no longer limiting the release of the geetools package. This is an attempt to restore all these cool functionalities.

[fitoprincipe]

Hi @12rambau and @eisracz83-cloud, before merging I'd like to raise my voice in this. IMHO it's not a good idea to restore ee-extra dependency. I am not against ee-extra but I think that users can import it and use it at will. I understand that this packages are similar and even some functions are (almost) the same (like matchHistogram), but let the user decide. Probably, many users will just import both and pick whatever suits them.

[12rambau]

ee-extra is multi-purpose lib that is available to users in python using https://github.com/davemlz/eemont that is not maintained anymore and took a different take than us on the extension pattern (see the docs). importing it prevents you from using it to chain computation and forces us to reimplement functions that are already available there. I preferred this option rather than reinventing the wheel as they are even more low level than us

[fitoprincipe]

I understand your point, but I'm still not 100% convinced, specially knowing that is not maintained anymore (as you mentioned). Let's do it and see how it evolves.