WIP: Improve whole logic for approval workflow

[sagargg]

• Avoided complex logic on approval flow.
• Removed extra metadata publish status and use the core state for storing publishing status.
• Users cannot edit dataset that are already submitted for review.
• Avoided complex templates overriding making minimal changes.
• Added unit tests.

Note: This only works for CKAN > v2.10.x

[ivanrvpereira]

Any chance of this being merged soon?

[sagargg]

@gavram Do you think we can merge this ?

[valentinmirchev]

@sagargg @gavram do you have any updates on this PR? Should we expect a merge in the following days? Weeks? Months?