protolint: configure protolint and fix the protolinting issues

This PR addresses the following:
- Install and Configure protolint to enforce the protobuf style guide rules in the CI.
- Fix the protolinting issues (package and import ordering) while maintaining the comaptibility.

lnrpc/devrpc/dev.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "lightning.proto";
-
 package devrpc;
 
+import "lightning.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/devrpc";
 
 /*

lnrpc/invoicesrpc/invoices.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "lightning.proto";
-
 package invoicesrpc;
 
+import "lightning.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/invoicesrpc";
 
 /*

lnrpc/lnclipb/lncli.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "verrpc/verrpc.proto";
-
 package lnclipb;
 
+import "verrpc/verrpc.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/lnclipb";
 
 message VersionResponse {

lnrpc/peersrpc/peers.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "lightning.proto";
-
 package peersrpc;
 
+import "lightning.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/peersrpc";
 
 // Peers is a service that can be used to get information and interact

lnrpc/routerrpc/router.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "lightning.proto";
-
 package routerrpc;
 
+import "lightning.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/routerrpc";
 
 /*

lnrpc/walletrpc/walletkit.proto

@@ -1,10 +1,10 @@
 syntax = "proto3";
 
+package walletrpc;
+
 import "lightning.proto";
 import "signrpc/signer.proto";
 
-package walletrpc;
-
 option go_package = "github.com/lightningnetwork/lnd/lnrpc/walletrpc";
 
 /*

lnrpc/walletunlocker.proto

@@ -1,9 +1,9 @@
 syntax = "proto3";
 
-import "lightning.proto";
-
 package lnrpc;
 
+import "lightning.proto";
+
 option go_package = "github.com/lightningnetwork/lnd/lnrpc";
 
 /*