This can happen if the user has Galaxy open on 2 windows, and they changed the panel view, it will show up on one, and would keep loading on the other since the panel isn't populated (panel string is stored in `localStorage` and panel views in the pinia store; both don't get updated simultaneously.

... as this also fixes the "could not find icon" error.

Fixes part 1 of galaxyproject#17150

If you reloaded `ToolsList` with no filters, instead of showing the entire toolset, it would show no results. This was because `itemsLoaded` needed to be a reactive computed value instead of a ref.

Tools with `/` in their id couldn't be unfavorited because the URI wouldn't be encoded