This PR solves the issue of there being both "<url>/" and "<url>" paths, that in the builder-web context shouldn't mean different things.
The slashes are now removed using a `Dream` middleware, and the request is redirected using a permanent redirect (that doesn't change the method used): https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Location
Notable changes:
* Trailing slashes from the hardcoded link urls were removed, as unneccesary redirects are then avoided.
* All links in `Views` were rewritten to be absolute instead of relative.
* As `Dream` deprecated `path` - `Utils.Path` was created containing some helpers for manipulating paths. *Note that `String.split_on_char` has a different semantics.*
* A blacklist `routeprefix_blacklist_when_removing_trailing_slash` was added, containing `Dream` route-prefixes to ignore.
* Only `GET` and `HEAD` requests are redirected.
* `redirect_parent` helper was rewritten using new `Utils.Path` functions to avoid brittle string manipulation + fixed the edgecase of redirecting to `/`.
* Added `Uri` dependency to make URL manipulation safer.
Co-authored-by: rand00 <oth.rand@gmail.com>
Co-authored-by: Reynir Björnsson <reynir@reynir.dk>
Reviewed-on: https://git.robur.io/robur/builder-web/pulls/80
Co-authored-by: rand <rand@r7p5.earth>
Co-committed-by: rand <rand@r7p5.earth>
