move sharing code from cs3org/reva

[C0rby]

Sorry about this huge PR.

This pull request moves the sharing code from https://github.com/cs3org/reva to this repo.
To do before merging:

• Check if anything changed in reva in the meantime
  • If so, implement the changes here
• Run the acceptance tests

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[ownclouders]

Here is an overview of what got changed by this pull request:

Clones added
============
- pkg/service/v0/shares/create.go  25
- pkg/service/v0/shares/get.go  11
- pkg/service/v0/shares/shares.go  4
- pkg/service/v0/shares/remove.go  8
- pkg/service/v0/shares/pending.go  10
- pkg/service/v0/shares/list.go  3
- pkg/service/v0/shares/update.go  13
         

See the complete overview on Codacy