rpc: update new supply commit calls to use the global universe server rate limiter

This ensures that these queries are also rate limited, as they'll be
exposed to the outside world depending on config setting.

Author: Roasbeef

rpcserver.go

@@ -4223,6 +4223,12 @@ func (r *rpcServer) FetchSupplyCommit(ctx context.Context,
 	req *unirpc.FetchSupplyCommitRequest) (
 	*unirpc.FetchSupplyCommitResponse, error) {
 
+	// Check the rate limiter to see if we need to wait at all. If not then
+	// this'll be a noop.
+	if err := r.proofQueryRateLimiter.Wait(ctx); err != nil {
+		return nil, err
+	}
+
 	groupPubKey, err := unmarshalGroupKey(
 		req.GetGroupKeyBytes(), req.GetGroupKeyStr(),
 	)
@@ -4794,6 +4800,12 @@ func (r *rpcServer) InsertSupplyCommit(ctx context.Context,
 	req *unirpc.InsertSupplyCommitRequest) (
 	*unirpc.InsertSupplyCommitResponse, error) {
 
+	// Check the rate limiter to see if we need to wait at all. If not then
+	// this'll be a noop.
+	if err := r.proofQueryRateLimiter.Wait(ctx); err != nil {
+		return nil, err
+	}
+
 	groupPubKey, err := unmarshalGroupKey(
 		req.GetGroupKeyBytes(), req.GetGroupKeyStr(),
 	)