Add disabled reason to projects

[MatthewWiddop]

Description

Adds a way of tracking the reason for a project to be hidden.

Updated actions:

Prompt for a reason for hiding a project:

Display information about the project, including the hidden reasons and current status:

I modified /project/hide and split /project/hide-unhide-many into two routes: /project/hide-many and /project/unhide-many. This is because they now perform different actions.

Closes #29

Type of Change

Delete options that do not apply:

• New feature (non-breaking change which adds functionality)
• Refactor (code changes that doesn't affect functionality)

Is this a breaking change?

• Yes
• No

[MatthewWiddop]

As mentioned before, I've introduced a new UnhidePopup for selecting and removing reasons for projects being hidden. Reasons are sorted by frequency (how many projects have this hidden reason). Note that single projects can be selected as well.

/project/unhide and project/unhide now require a hidden_reason to be specified for removal. For each project in the request, any matching hidden_reason is removed. There isn't much validation for the request, but I can add more if required.

Here's what UnhidePopup looks like (I'm no artist):