Add GNOME Search Provider integration

[OutCraft-Mods]

Thanks for creating this awesome application! It's very useful and way better than the default GNOME Dictionary.

This PR adds GNOME search integration and closes #41.
The search_provider.in file uses some code form Wike.

This is my first time contributing code to an application built for linux, so I might have missed something.
Please review the code before merging.

[mufeedali]

This looks nice, thanks for working on it! I don't use GNOME much anymore, so I'm not able to test if it works or if it looks nice UI-wise right away but I'll try to test it ASAP. In the meanwhile, can you apply ruff's formatting to the search provider file?

[OutCraft-Mods]

Hi, thanks for taking the time to look at the code.
I just formatted the file using the ruff formatter.
Let me know if there's anything else I can to to help.

[mufeedali]

That looks nice :)

There are stuff I might change, but I love it enough that I'll just merge it for now. Huge thanks for working on this! Always meant to do this but display scaling issues have kept me away from GNOME for a while now.