Resolve "Search playlist unexpectedly triggers keyboard sortcut commands"

Closes #902 (closed)

On artists, albums, radios and playlists pages, it ensure we don't trigger a full page reload when search or other filters are specified. This means the focus isn't lost anymore when the data is refreshed, leading to a better user experience and overall, and preventing the issue described in #902 (closed): searching something, losing focus, meaning subsequent key presses are considered keyboard shortcuts.

Also fixed a small, unrelated crash when browsing artists and albums with an empty tag=? parameter in URL

cc @funkwhale/reviewers-front