testutil/validatormock: refactor vmock

[corverroos]

Refactor validatormock to support lookahead for relevant duties like DutyPrepareAggregator and DutySyncContribution.

category: refactor
ticket: #2400

[codecov]

Codecov Report

Attention: 407 lines in your changes are missing coverage. Please review.

Comparison is base (1ca2b47) 53.77% compared to head (5f7139a) 53.49%.
Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2545      +/-   ##
==========================================
- Coverage   53.77%   53.49%   -0.28%     
==========================================
  Files         200      202       +2     
  Lines       27132    27339     +207     
==========================================
+ Hits        14589    14624      +35     
- Misses      10719    10892     +173     
+ Partials     1824     1823       -1     

Files	Coverage Δ
cmd/createdkg.go	72.58% <100.00%> (ø)
core/scheduler/scheduler.go	74.89% <100.00%> (+0.10%)	⬆️
eth2util/network.go	67.39% <ø> (ø)
testutil/compose/run.go	81.00% <100.00%> (ø)
app/app.go	6.72% <0.00%> (ø)
cmd/createcluster.go	59.82% <0.00%> (ø)
testutil/compose/auto.go	0.00% <0.00%> (ø)
app/vmock.go	0.00% <0.00%> (ø)
testutil/validatormock/propose.go	29.57% <54.83%> (ø)
testutil/validatormock/meta.go	0.00% <0.00%> (ø)
... and 1 more

... and 9 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[xenowits]

LGTM!