cmd, eth, internal, les: add txfee cap (#21212)

* cmd, eth, internal, les: add gasprice cap

* cmd/utils, eth: add default value for gasprice cap

* all: use txfee cap

* cmd, eth: add fix

* cmd, internal: address comments

cmd/geth/main.go

@@ -186,6 +186,7 @@ var (
 		utils.IPCPathFlag,
 		utils.InsecureUnlockAllowedFlag,
 		utils.RPCGlobalGasCap,
+		utils.RPCGlobalTxFeeCap,
 	}
 
 	whisperFlags = []cli.Flag{

cmd/geth/usage.go

@@ -176,6 +176,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.GraphQLCORSDomainFlag,
 			utils.GraphQLVirtualHostsFlag,
 			utils.RPCGlobalGasCap,
+			utils.RPCGlobalTxFeeCap,
 			utils.JSpathFlag,
 			utils.ExecFlag,
 			utils.PreloadJSFlag,