Move google/nearby external submodule and `gfps_service` component to separate repo

[finger563]

Is your feature request related to a problem?

Right now full / deep clone (recursing through all the submodules) takes a little while because the google/nearby repository is quite large / has a lot of submodules. We're actually not using much of what they've got there, and on top of it many users may not be wanting to use the gfps_service component.

Describe the solution you'd like.

Move gfps_service component to a separate repository and move the google/nearby (which is currently under espp/external/nearby) to be within that component's detail folder instead.

Describe alternatives you've considered.

Continuing to force people to fully download google/nearby just to use this repo?

Additional context.

No response

[finger563]

https://github.com/esp-cpp/espp_gfps_service

[finger563]

Now that we've published each component to the idf component registry with #419 / #312, and as part of that change have made the published gfps_service component no longer bundle the whole google/nearby but instead just the google/nearby/embedded subfolder, the build download is significantly smaller, removing the need for this change. Since the other repo already exists, I may update this repo accordingly, but it's no longer needed.