feat: add GetPowerTableByInstance method to F3 (#1026)

* feat: add GetCertPowerTable method to F3

Adds a method to get the power table (committee) used to validate
the specified instance.

Signed-off-by: Jakub Sztandera <[email protected]>

* rename

Signed-off-by: Jakub Sztandera <[email protected]>

---------

Signed-off-by: Jakub Sztandera <[email protected]>

Author: Kubuxu

f3.go

@@ -126,6 +126,14 @@ func (m *F3) GetCert(ctx context.Context, instance uint64) (*certs.FinalityCerti
 	return nil, ErrF3NotRunning
 }
 
+// GetPowerTableByInstance returns the power table (committee) used to validate the specified instance.
+func (m *F3) GetPowerTableByInstance(ctx context.Context, instance uint64) (gpbft.PowerEntries, error) {
+	if state := m.state.Load(); state != nil {
+		return state.cs.GetPowerTable(ctx, instance)
+	}
+	return nil, ErrF3NotRunning
+}
+
 // computeBootstrapDelay returns the time at which the F3 instance specified by
 // the passed manifest should be started.
 func (m *F3) computeBootstrapDelay() (time.Duration, error) {