feat: register wslview as a XDG MIME applications

[jaxvanyang]

This change allows desktop environment to find and use wslview to open registered MIME types.

Description

wslview.desktop was installed in /usr/share/wslu/ before, which has no effect. I move it to the standard /usr/share/applications/, so that it can be used by desktop environment tools, e.g., xdg-open. And this solves the problem that wslview cannot registered itself as the default browser on Arch Linux.

Types of changes

Breaking change (fix or feature that would cause existing functionality to not work as expected) are no longer accepted

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] I have read Code of Conduct and Contributing documentations.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.