Associate QGIS MIME types with the QGIS application entry

[MattF-NSIDC]

Resolves #55

[github-actions]

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[MattF-NSIDC]

The changes so far aren't working. I think this is successfully adding the QGIS mimetypes and file extension associations to the database, but the application isn't properly associated with them yet. I think I need to run update-desktop-database to pick up the ~/Desktop/*.desktop file(s)...

[MattF-NSIDC]

Got it working. Placing the .desktop file in ~/Desktop successfully creates an icon that can be double-clicked to open that application, but doesn't add an entry to the applications menu or set up MIME type associations with that application. For that, we also need: A MimeType attribute in the .desktop file, an XML MIME type definition file, and to register those with the desktop and mime databases.

I think repo2docker could potentially be enhanced to handle these in a standard way. Perhaps:

• a standard directory for .xml MIME type definitions which will get copied into the image at ~/.local/share/mime/packages/. and registered into the database
• another standard directory for .desktop application definitions which will get copied into the image at ~/.local/share/applications/. and registered into the database
• a standard file containing the names (in-image paths?) of .desktop entries that should be symlinked to the desktop.

[yuvipanda]

Thanks a lot, @MattF-NSIDC! This lgtm :)