feature: Add VRF based committee elections

[Yawning]

• Bump the curve25519-voi import
• Implement TupleHash
• Make common/crypto/signature VRF aware
• Generate/Load the VRF signing key as part of the node identity
• Add the VRF signing key to the node descriptor
• Validate the VRF signing key contained in the node descriptor if present
• Add back deterministic epochs
• Consensus support for VRF submissions
• Nodes submit VRF proofs each epoch
• Use VRF proofs to select from an eligible entity's validator nodes
• Use VRF proofs + sortition to do elections
• Unbreak the tests
• Unfuck the byzantine node somehow
• Rip out the old PVSS code
• Rip out the old deterministic seed based election code.
• Add the relevant fixgenesis stuff

Testing:

• Switch the e2e tests to exercise the new VRF code
• Work around oasis-test-runner/scenario/e2e/genesis_file makes it impossible to remove parameters #4374
• Add byzantine VRF tests (not much to do here)

Documentation:

• Update/edit the ADR to match reality.

Post upgrade steps for the next breaking upgrade:

• Remove the backward compatibility PVSS raw CBOR message field in the node descriptor. (Filed as go/common/node: Remove the old PVSS public key placeholder #4393).
• Enforce that a VRF signing key is always contained in the node descriptor (Filed as go/registry: Make submitting a VRF signing key mandatory #4394).

[codecov]

Codecov Report

Merging #4248 (d510d42) into master (81fa2dd) will decrease coverage by 0.08%.
The diff coverage is 69.50%.

❗ Current head d510d42 differs from pull request most recent head 0a0873c. Consider uploading reports for the commit 0a0873c to get more accurate results

@@            Coverage Diff             @@
##           master    #4248      +/-   ##
==========================================
- Coverage   69.15%   69.07%   -0.09%     
==========================================
  Files         411      413       +2     
  Lines       47510    46910     -600     
==========================================
- Hits        32857    32401     -456     
+ Misses      10615    10551      -64     
+ Partials     4038     3958      -80     

Impacted Files	Coverage Δ
go/beacon/api/grpc.go	20.57% <ø> (+2.29%)	⬆️
go/common/crypto/signature/signers/remote/grpc.go	31.29% <0.00%> (-6.32%)	⬇️
go/common/node/node.go	73.40% <ø> (ø)
go/consensus/tendermint/apps/beacon/beacon.go	73.77% <ø> (ø)
.../consensus/tendermint/apps/roothash/state/state.go	73.84% <ø> (+1.81%)	⬆️
go/staking/api/slashing.go	100.00% <ø> (+22.22%)	⬆️
...o/common/crypto/signature/signers/plugin/plugin.go	57.62% <14.28%> (-2.74%)	⬇️
go/beacon/api/api.go	50.00% <25.00%> (+7.89%)	⬆️
...n/crypto/signature/signers/memory/memory_signer.go	61.81% <33.33%> (-3.49%)	⬇️
go/consensus/tendermint/apps/roothash/roothash.go	73.87% <33.33%> (-0.62%)	⬇️
... and 90 more

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