[New Feature]: Search Engine functionality with browser selection and fallback to xdg-open

[bonettibruno24]

This pull request introduces the Search Engine functionality to the extension, enhancing its capabilities for web searches. Users can now enable or disable the Search Engine feature, select their preferred search engine provider (e.g., DuckDuckGo, Bing, Brave, among others), and choose which browser application to open search results.

A fallback mechanism has been implemented: if the selected browser is not installed on the system, the default browser is used via xdg-open, ensuring robust behavior across different environments.

Changes:

Added a toggle to enable/disable the Search Engine feature.
Added a dropdown to select the preferred Search Engine provider.
Added a dropdown to select the browser application for opening search results.
Implemented a fallback to system default browser if the selected browser is unavailable.
Updated CHANGELOG.md with a new release entry for this feature.

[bonettibruno24]

@icedman Are you present?

[icedman]

It is better to add this searchProvider as a separate extension to gnome. I had a couple of searchProviders integrated but decided to remove them as it would add more "breakables". Thanks!

[Normoxd]

Would love to see a feature like DuckDuckGo !bangs to move between search engines.

[shrutsureja]

would love to use this feature at the earliest

[bonettibruno24]

dsada

would love to use this feature at the earliest

I know it's an extremely useful feature; I use it every day for work. I'll be posting the extension soon. Follow my GitHub; I'll post it shortly.