UI repository handling

[erasta]

There are now multiple repositories that are on the file system (mapped to /user/abc/def/... path or something)
Suggestion:
Have one repository mapping json (mother_of_all_repos.json) that will have the pathes of all the above (maybe with name)
When a user enters the UI, the user can set the location of that main json.
The UI will then read that json, and then read all repositories that are listed there, and have info on all the data sources in them.
Then when a user opens a project, a list of the repositories will be shown in a tree with all their data sources. Those will have checkboxes which are initially marked, but the user can uncheck it.
Later, the project will be aware of the repositories, so a user would be able to add, remove, or refresh either a data source or a repository of data sources on the project.
Later on this will enable us not to rely on the default project for initializing the sources of a new project.

According to talk with @yehudarav