Tag actions take no effect unless TagPolicy is enabled

Related to #134 (closed) and pleroma#2010 (closed)

Personally I think the short-term solution to this problem is that Pleroma should have TagPolicy enabled by default.

But if it's disabled, it's deceptive to the user that these actions will actually do anything. Maybe they should be greyed out if TagPolicy is disabled, or something.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information