perf: parse chain-id from big genesis file could be slow (backport #18204) (#18267)

Co-authored-by: yihuang <huang@crypto.com>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>

server/util.go

@@ -475,12 +475,16 @@ func DefaultBaseappOptions(appOpts types.AppOptions) []func(*baseapp.BaseApp) {
 	chainID := cast.ToString(appOpts.Get(flags.FlagChainID))
 	if chainID == "" {
 		// fallback to genesis chain-id
-		appGenesis, err := genutiltypes.AppGenesisFromFile(filepath.Join(homeDir, "config", "genesis.json"))
+		reader, err := os.Open(filepath.Join(homeDir, "config", "genesis.json"))
 		if err != nil {
 			panic(err)
 		}
+		defer reader.Close()
 
-		chainID = appGenesis.ChainID
+		chainID, err = genutiltypes.ParseChainIDFromGenesis(reader)
+		if err != nil {
+			panic(fmt.Errorf("failed to parse chain-id from genesis file: %w", err))
+		}
 	}
 
 	snapshotStore, err := GetSnapshotStore(appOpts)