Various fixes in preparation of 30

[artonge]

Change	Before	After
fix: Limit upload picker custom css to header
dix: Populate photosLocationFolder on init
fix: Make route name unique		Less warnings in browser console
chore: Fix typo in collection.js		No more typo
chore: Use NcSelect label		Less warnings in browser console and less custom code
fix: Don't proceed with album creation if it fails		Prevents storing undefined in the albums store
chore: Explicitly require @nc/router		Make linter happy
fix: Specify a source for the tmp local album		Less warnings in browser console
fix: Declare photosLocationFolder as computed		Fix uploading files from an album
fix: Check if album is defined before accessing it in AlbumContent		Less errors in browser console
chore: Remove useless v-if in AlbumContent		-
fix: Reinit the files in File.vue		Fix rendering previews when adding a file to an album
fix: Center empty content in empty albums		To make me happy
feat: Display the upload button for empty albums		As it does not make sense to hide it in the first place

[nfebe]

LGTM