Add alternative backend support

[sdmg15]

Is there any plan to add alternative backend support? Frigate for example.

I already worked on adding it on this BDK-SP in this bitcoindevkit/bdk-sp#48.
Would be happy to work on adding it here also.

Thanks

cc @Sosthene00

[Sosthene00]

Yes I think that makes a lot of sense. @cygnet3

[cygnet3]

Frigate is definitely worth exploring. It will require a proper redesign of ChainBackend to accommodate both the current approach (BIP158-style scanning) and remote scanning with Frigate. I do think we want to move in that direction, so if you're willing to have a stab at it, be my guest.

[Sosthene00]

Just as an aside, implementing frigate support also gives us friglet support, I guess?