[v1.0.2 all platforms] tagging while downloads are in progress repeatedly clears tag input

[blahah]

reported by @npscience by email

Typing in the tag input in the detail view is impossible while downloads are happening because the view refreshes constantly, clearing the input.

The solution is to wrap the tag input in a cached element that doesn't refresh with the rest of the app using cache-component as we do for the search input. We probably need to do this for all inputs:

• [x] search
• [x] add tag
• [x] add datasource

[blahah]

All the inputs in the app are now cached and the issue is fixed. It will land in the next release - v1.0.3.