Support for group DReps

[l-br1]

This is to discuss what are the needs of group DReps and what are the options to handle registration and delegation in govtool

[l-br1]

@Ryun1

[phillewis]

Might be better to have this customer-driven rather than developer-driven, to avoid building solutions for presumed problems #YAGNI

There are many ways that group DReps could choose to operate, e.g.:

• Multi-sig with doxxed key-holders
• Single key with off-chain private or public governance
• Single key with on-chain governance using another token (e.g. as Minswap did for Catalyst)