Port accommodating '/' in dashboard tags

[jezdez]

Refs #48 (e.g. be89d48)

[alison985]

@jezdez The variable name TAGS_REGEX and some distinctive parts of the string don't exist in /client/app/ or /redash/ directories. I believe this is part of tag related things that Arik is working on right now. I'm going to mark this as blocked and we can test to make sure / are allowed in tags after those changes are merged upstream.

[alison985]

Slashes work for me locally now that we have merged upstream with the tags code.

[madalincm]

Verified as fixed in FF61(Win7x64) In stmo-rc
Tags containing "/" can be added to both dashboards and queries.
Marking bug as verified fixed.