feat: pool id extraction functions (#621)

Copy the get list of pool ID from (de)registration certificates functions
from https://github.com/cardano-foundation/cardano-ibc-incubator with minimal
modifications.

Signed-off-by: Chris Gianelloni <[email protected]>

Author: wolf31o2

ledger/verify_block_body.go

@@ -304,3 +304,23 @@ type DeRegisCert struct {
 	DeRegisEpoch  string
 	TxIndex       int
 }
+
+func GetListRegisCertPoolId(regisCerts []RegisCert) []string {
+        poolId := make([]string, 0)
+        if len(regisCerts) > 0 {
+                for _, cert := range regisCerts {
+                        poolId = append(poolId, cert.RegisPoolId)
+                }
+        }
+        return poolId
+}
+
+func GetListUnregisCertPoolId(deRegisCerts []DeRegisCert) []string {
+        poolId := make([]string, 0)
+        if len(deRegisCerts) > 0 {
+                for _, cert := range deRegisCerts {
+                        poolId = append(poolId, cert.DeRegisPoolId)
+                }
+        }
+        return poolId
+}