Don't manually replace whitespace during render (#10291)

Don't manually replace whitespace during render (#10291)

* Don't manually replace whitespace during render

For historical reasons Gitea manually alters the urlPrefix and replaces
a whitespace with a +. This Works for URLs, but we're also passing
urlPrefix to git calls and adding the + is breaking the tree path.

Goldmark will automatically convert a white space to the proper %20, so
we should leave the string as is which lets us pass it to git unmodified
and then let Goldmark fix it.

Also fixed separate bug in URLJoin I noticed while testing where it will
silently discard sections of a path that have # in them (possibly
others). We should just escape it first.

Fixes 10156

* Escape elems as well

* Revert "Escape elems as well"

This reverts commit 8bf49596fee6fac4d9da256cd1e90a0ec0183671.

* restart ci

* remove changes to URLJoin

* restart ci

Co-authored-by: techknowlogick <matti@mdranta.net>