Use server capabilities

[rullzer]

Replaces #2943
Should fix: #2815

By making use of the capabilities provided by the server we can provide a better UX.

1. Do not allow a user to remove expire date/password if the admin enforces it
2. Require a password from the user if this is enforced.

[dragotin]

Two questions/suggestions:

• I think we should have a Capabilities object that with proper methods, so that it reads:
  if( account()->capabilities()->pubLinkForcePassword() ) { ... instead of the map stuff we have now.
• Please do not use the QInputDialog. The dialog has a password field already, which should be made visible rather.

What do you think?

[rullzer]

• I think we should have a Capabilities object that with proper methods, so that it reads:
  if( account()->capabilities()->pubLinkForcePassword() ) { ... instead of the map stuff we have now.

I agree. Now the questions is where and how to do this. Do we do this on a as needed basis... so I create a shareCapabilities class where all that is properly parsed. Or do we do it in 1 place where we parse everything?

• Please do not use the QInputDialog. The dialog has a password field already, which should be made visible rather.

Yes, this should be changed indeed.

[rullzer]

@dragotin both your comments are address in the latest two commits...
Code should be better readable now and no annoying extra inputdialog anymore.

[ogoffart]

This should not be a pointer. Just make it a normal object like the QVariantMap was.

[rullzer]

@ogoffart thanks and fixed!

[ogoffart]

This looks wrong, you are not assinging anything.

The default generated copy constructor and operator are fine. Implementing them breaks the move sementic. (see "Rule of zero")

[rullzer]

Aaah you are right...