In the redirect controller, rather than URL-encoding the entire input
term before processing it, only URL-encode (the relevant parts of) it in
the URL that the redirect controller generates. This ensures that the
original input term can be pattern-matched appropriately.
Fixes#90.
On the home page, allow TikTok URLs to be entered as search terms for
the new category "TikTok URL", and redirect to a ProxiTok-compatible
URL when a valid one is entered.
Closes#58.
