Added spinners in share dropdown

Added spinners for the following actions:
- adding user
- removing user
- changing password
- toggling allowing upload
- setting a password
Add ID to markup to have the checkboxes in the right position
Prevent monkey clicking on labels

Clicking on labels while the spinner is there will not trigger the
hidden checkbox any more.
Merge pull request #11304 from owncloud/share-spinner

Added spinners in share dropdown