As far as possible I think the code is clearer if we use CRUD actions
rather than custom actions. This will make it easier to add the action
to remove votes in the next commit.
Note that we are adding this line as we need to validate it that a vote
can be created on a debate by the current user:
```authorize! :create, Vote.new(voter: current_user, votable: @debate)```
We have done it this way and not with the following code as you might
expect, as this way two votes are created instead of one.
```load_and_authorize_resource through: :debate, through_association: :votes_for```
This line tries to load the resource @debate and through the association
"votes_for" it tries to create a new vote associated to that debate.
Therefore a vote is created when trying to authorise the resource and
then another one in the create action, when calling @debate.vote_by (which
is called by @debate.register_vote).
The `hide` action was calling the `block` method while the `soft_block`
action was calling the `hide` method.
Combined with the fact that we also have a `block` permission which is
used in `ModerateActions` the logic was hard to follow.
Other than removing a redundant action, we're fixing two bugs when
blocking an author using the links in the public views:
* We were always redirecting to the debates index, even if we blocked
the author of a proposal or an investment
* We weren't showing any kind of success message
I'm doing this in preparation for the "Manager" ability, which will
require even more refactors of the abilities (for example,
manager can not modify their own account)
