Don't use depth infinity anymore to get the folders e2ee status

Don't use depth infinity anymore to get the folders e2ee status

This way we avoid the expensive SQL query on the server at the price of
more round-trips since we're doing the recursive traversal by hand now.

Also it turns out this depth was used for all the other propfind calls
during sync when we want fresher information regarding a folder. This
was very inefficient in all cases and won't happen anymore.

Signed-off-by: Kevin Ottens <kevin.ottens@nextcloud.com>