HyperTextView: add local path detection

### Problem

HyperTextView lacks detecting a local path (~/something or /home/user/something) to a file or folder that could be opened via XDG-Open

i might in a far future implement this in a fork of HyperTextView for my needs, and could eventually if that happens, contribute it as a new custom widget, or an expansion of this one.

### Proposal

Add regex for path to files and folders, which opens if clicked in the same way

as the packaged software doing this may be limited by flatpak, this could be optional - Or check whether the file or folder exists

### Prior Art (Optional)

_No response_