add /:channel/tags

[4www]

List all tags and order them by popularity, most occurrences first.

• track model now have a computed property track.tags
• add a /channel/tags route
• list selected tags, those in the channel.body
• list tracks with no tags, so it is easier to start editing

What we can think about in the future:

• show how many tracks are in a tag; ex: house (200)
• should the tags link display all tags on the tags page, or continue linking to /:channel/tracks?search=#tag
• where to list all tracks without discogs
• where to list all tracks with broken media links
• how to mass edit multiple tracks at once, add tags. remove tags, clean things up
• how to rename a tag; ex: rename #PM to #pm

[oskarrough]

This is super cool!!

On the channel page, the /tags link only appears if you have hashtags in your channel.body, or how does it work?

https://deploy-preview-405--radio4000.netlify.com/oskar/ko002
https://deploy-preview-405--radio4000.netlify.com/oskar/tags