Arguably not meaningful, as it adds the scanner yet not the RPC, and no signing
code since modular-frost doesn't support no-std yet. It's a step in the right
direction though.
common/ is now only run when common is edited. crypto/ when common/ or crypto/.
coins/ when common/ or crypto/ or coins/. The rest of the tests are run
whenever any package is edited (as they're all inter-connected).
Impls a LocalP2p for testing.
Moves rebroadcasting into Tendermint, since it's what knows if a message is
fully valid + original.
Removes TributarySpec::validators() HashMap, as its non-determinism caused
different instances to have different round robin schedules. It was already
prior moved to a Vec for this issue, so I'm unsure why this remnant existed.
Also renames the GH no-std workflow from the prior commit.
