asset: add IsTransferRoot func

IsTransferRoot returns true if this asset represents a root transfer. A
root transfer is an asset that is neither a genesis asset nor contains
split commitment witness data.

Author: gijswijs

asset/asset.go

@@ -1383,6 +1383,13 @@ func (a *Asset) HasSplitCommitmentWitness() bool {
 	return IsSplitCommitWitness(a.PrevWitnesses[0])
 }
 
+// IsTransferRoot returns true if this asset represents a root transfer. A root
+// transfer is an asset that is neither a genesis asset nor contains split
+// commitment witness data.
+func (a *Asset) IsTransferRoot() bool {
+	return !a.IsGenesisAsset() && !a.HasSplitCommitmentWitness()
+}
+
 // IsUnSpendable returns true if an asset uses the un-spendable script key and
 // has zero value.
 func (a *Asset) IsUnSpendable() bool {