Run DKG on contracts instead of Shuttermint

[jannikluhn]

Replace Shuttermint with a contracts based system.

• Remove all Shuttermint related code and DB tables.
• Sync DKG and ECIES key registration events (see Implement DKG contracts contracts#10)
• Send DKG and ECIES key registration transactions when needed
• Preserve the existing interface with the decryption key generation code
• Backwards compatibility is not required. Keypers will not update their existing setups but deploy new ones
• Reorg safety is not required yet
• Update the mise test setup
• Add end to end tests

[jannikluhn]

rolling-shutter PR: #707
contracts PR: shutter-network/contracts#9
shutter-keyper-deployment PR: shutter-network/shutter-keyper-deployment#71

Tests with four VPS instances on Chiado were successful.

[ylembachar]

• reflect on which metrics to add

[jannikluhn]

The rolling shutter PR has been merged to the new branch on-chain-dkg. We can open individual pull requests towards it for fixes and features.