feat(files): add support for Files API (personal and shared spaces)

[nunogoncalves03]

We have recently updated the Management API to include new endpoints for managing files in personal and shared spaces. Thus, we would like to update the Python SDK to support these resources as well.

Since the methods for stage files and personal/shared space files are quite similar, we would like to refactor the Python SDK by introducing an abstract class called FileLocation. This class will be implemented by Stage and FileSpace, which will be used to interact with the Files API for personal and shared files.

This PR introduces the FilesManager and FileSpace classes, allowing us to manage files in personal and shared spaces.

Note that this PR depends on #45 and only affects the Python SDK. To keep the PRs smaller, I will include the Fusion SQL changes related to the Files API in a separate PR.

cc: @ricardoasmarques @kanitsharma

[nunogoncalves03]

Note that I left some TODO comments regarding whether we should remove the directory-related methods from the FileLocation abstract class. Ideally, both stage and personal/shared spaces would support folders and files; however, currently, personal/shared spaces only support files. Therefore, we have two alternatives:

1. Remove the directory methods from the abstract class and add them only in the Stage class as additional methods.

2. Maintain the directory methods in the abstract class to keep it future-proof and more generic, as we plan to implement folder support in personal/shared spaces in the future. In this case, we would return an operation not supported error in the FileSpace class.

[kesmit13]

I think leaving the unsupported methods in the API and just raising errors is ok. It makes it easier for the user to determine what's wrong if they attempt to use it, although it does make those show up in auto-complete like they are supported. I think the way you have it implemented is the lesser of evils.