[FEATURE] Ability to Specify Custom Search Provider as Seen in Nova Launcher

[Syberkonda]

Describe the feature

One of my favorite features in Nova Launcher is the ability to set a custom search provider using a URL. This allows me to use Brave Search even though Nova doesn't officially support it in their settings.

Why would it be useful to add?

This would enable users to add their own search engines in addition to Startpage and Google.

Did the feature exist in Lawnchair v2? (Play Store version)

Not that I am aware of

Example(s)

Additional context

No response

[ohshazbot]

Dupe of #4220 ?