FIP-0043 Introduce Domain Separation FIP

[geoff-vball]

First draft of a FIP for adding Signature Domain Separation Tags, see #387.

An open question is how to deal with BLS Signature Aggregation. Feedback welcome!

[anorth]

I think this draft is not quite in a clear enough state to merge. The specification for protocol level changes is not clear, and there are quite a few open questions. It's been sitting here for a while. I'd suggest we close this PR unless it will be actively worked on in the near future. The FIP number can stay reserved for when someone does pick it up, though.

[jennijuju]

converting to draft for now, @geoff-vball plz reopen for review when its ready again

[Kubuxu]

It would be great if FIP-0044 included DST as well.

[Kubuxu]

After thinking about it more, I would upgrade the "great" to "strong should".
FIP-0044 is a standard we want other people to adopt, the lack of DST will cause long-term security issues and the transition to DST enabled version of FIP-0044 will be hard.

cc @Stebalien

[kaitlin-beegle]

Closing for now. Seems like the benefits of this FRC have been incorporated as part of follow-on FIPs, and that this draft is not currently moving towards readiness. Feel free to reopen if that changes!