Support local anchors with # in the links

[lorenzo-cavazzi]

Motivation

Local anchors (linking to local sections with #) don't work in our file preview; the link doesn't contain the local file name, just the first part of the URL and then #local-ref. See this discussion for more context #2573 (comment).

Perhaps we can try to handle it in RenkuMarkdownWithPathTranslation: catching the links starting with # might not be too hard

Proposal

Time frame this to a day; if there are no reasonable progressions after half a day, let's postpone/drop it.

[lorenzo-cavazzi]

There won't be a unified file browser in Renku 2.0.