Improve analyze participation

[dB2510]

Problem to be solved

Currently tracker component analyzes participation based on share indexes obtained from various events. We assume those events to be valid. However, there are some possibilities where we get events from byzantine peers in the cluster. In that case tracker will report inaccurate results. Therefore we need to validate each event as part of analyze participation. Some examples of byzantine behavior:

• Incorrect set of pubkeys provided by a peer.
• Duty for which data has been sent by a peer wasn't scheduled/expected.

Proposed solution

Validation needs to be added as part of analyze participation to analyze events corresponding to each duty. Validations can be done in the following manner:

• Validate if peer triggered event is expected or not:
  • If scheduler event present for that duty+pubkey, then it is expected
  • This is trivial DutyAttester, DutyProposer and DutyBuilderProposer.
  • Can use DutyProposer events to verify if DutyRandao is expected.
  • Cannot do this for validatorAPI triggered duties like DutyExit or DutyBuilderRegistration, so assume these are valid.
  • If event is unexpected, log a warn and increment unexpected events counter.

Note: This ticket assumes that partial signatures obtained from parsigex are valid which is part of #217 . This ticket should be closed after #217.