feat: validator dashboard template (hyperlane-xyz#4097)

### Description

Replaces the old (and probably deprecated) validator dashboard template
with a new one that shows metrics that can be alerted on:
![Screenshot 2024-07-04 at 14 25
53](https://github.com/hyperlane-xyz/hyperlane-monorepo/assets/23065004/08ba370d-154a-4c45-91f7-2f6c9167f5a9)


### Drive-by changes

Uses the "External Sharing" grafana feature to generate a json that
removes AW-specific data from the relayer template

Author: daniel-savu

tools/grafana/easy-relayer-dashboard-external.json tools/grafana/easy-relayer-dashboard-template.json

@@ -1,4 +1,35 @@
 {
+  "__inputs": [
+    {
+      "name": "DS_GRAFANACLOUD-ABACUSWORKS-PROM",
+      "label": "grafanacloud-abacusworks-prom",
+      "description": "",
+      "type": "datasource",
+      "pluginId": "prometheus",
+      "pluginName": "Prometheus"
+    }
+  ],
+  "__elements": {},
+  "__requires": [
+    {
+      "type": "grafana",
+      "id": "grafana",
+      "name": "Grafana",
+      "version": "11.2.0-72576"
+    },
+    {
+      "type": "datasource",
+      "id": "prometheus",
+      "name": "Prometheus",
+      "version": "1.0.0"
+    },
+    {
+      "type": "panel",
+      "id": "timeseries",
+      "name": "Time series",
+      "version": ""
+    }
+  ],
   "annotations": {
     "list": [
       {
@@ -18,13 +49,13 @@
   "editable": true,
   "fiscalYearStartMonth": 0,
   "graphTooltip": 0,
-  "id": 66,
+  "id": null,
   "links": [],
   "panels": [
     {
       "datasource": {
         "type": "prometheus",
-        "uid": "grafanacloud-prom"
+        "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
       },
       "description": "There shouldn't be abrupt changes, especially for a specific pair",
       "fieldConfig": {
@@ -105,7 +136,7 @@
         {
           "datasource": {
             "type": "prometheus",
-            "uid": "grafanacloud-prom"
+            "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
           },
           "editorMode": "code",
           "expr": "sum by (origin,remote)(round(increase(hyperlane_messages_processed_count[5m])))",
@@ -122,7 +153,7 @@
     {
       "datasource": {
         "type": "prometheus",
-        "uid": "grafanacloud-prom"
+        "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
       },
       "fieldConfig": {
         "defaults": {
@@ -202,7 +233,7 @@
         {
           "datasource": {
             "type": "prometheus",
-            "uid": "grafanacloud-prom"
+            "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
           },
           "editorMode": "code",
           "expr": "sum by (remote, queue_name)(\n    hyperlane_submitter_queue_length{queue_name=\"prepare_queue\"}\n)",
@@ -218,7 +249,7 @@
     {
       "datasource": {
         "type": "prometheus",
-        "uid": "grafanacloud-prom"
+        "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
       },
       "fieldConfig": {
         "defaults": {
@@ -298,7 +329,7 @@
         {
           "datasource": {
             "type": "prometheus",
-            "uid": "grafanacloud-prom"
+            "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
           },
           "disableTextWrap": false,
           "editorMode": "code",
@@ -318,7 +349,7 @@
     {
       "datasource": {
         "type": "prometheus",
-        "uid": "grafanacloud-prom"
+        "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
       },
       "fieldConfig": {
         "defaults": {
@@ -398,7 +429,7 @@
         {
           "datasource": {
             "type": "prometheus",
-            "uid": "grafanacloud-prom"
+            "uid": "${DS_GRAFANACLOUD-ABACUSWORKS-PROM}"
           },
           "disableTextWrap": false,
           "editorMode": "code",
@@ -426,7 +457,6 @@
     "from": "now-7d",
     "to": "now"
   },
-  "timeRangeUpdatedDuringEditOrView": false,
   "timepicker": {},
   "timezone": "browser",
   "title": "Easy Dashboard (External Sharing Template)",