AzureMonitor: Alerting for Azure Application Insights (#19381)

* Convert Azure Application Insights datasource to Go

Allows for alerting of Application Insights data source

Closes: #15153

* Fix timeGrainReset

* Default time interval for querys for alerts

* Fix a few rename related bugs

* Update readme to indicate App Insights alerting

* Fix typo and add tests to ensure migration is happening

* Address code review feedback (mostly typos and unintended changes)

pkg/tsdb/azuremonitor/test-data/applicationinsights/1-application-insights-response-raw-query.json

@@ -0,0 +1,27 @@
+{
+  "tables": [
+    {
+      "name": "PrimaryResult",
+      "columns": [
+        {
+          "name": "timestamp",
+          "type": "datetime"
+        },
+        {
+          "name": "value",
+          "type": "int"
+        }
+      ],
+      "rows": [
+        [
+          "2019-09-13T01:02:03.456789Z",
+          1
+        ],
+        [
+          "2019-09-13T02:02:03.456789Z",
+          2
+        ]
+      ]
+    }
+  ]
+}

pkg/tsdb/azuremonitor/test-data/applicationinsights/2-application-insights-response-raw-query-segmented.json

@@ -0,0 +1,43 @@
+{
+  "tables": [
+    {
+      "name": "PrimaryResult",
+      "columns": [
+        {
+          "name": "timestamp",
+          "type": "datetime"
+        },
+        {
+          "name": "value",
+          "type": "int"
+        },
+        {
+          "name": "segment",
+          "type": "string"
+        }
+      ],
+      "rows": [
+        [
+          "2019-09-13T01:02:03.456789Z",
+          1,
+          "a"
+        ],
+        [
+          "2019-09-13T01:02:03.456789Z",
+          2,
+          "b"
+        ],
+        [
+          "2019-09-14T02:02:03.456789Z",
+          3,
+          "a"
+        ],
+        [
+          "2019-09-14T02:02:03.456789Z",
+          4,
+          "b"
+        ]
+      ]
+    }
+  ]
+}

pkg/tsdb/azuremonitor/test-data/applicationinsights/3-application-insights-response-metrics-single-value.json

@@ -0,0 +1,9 @@
+{
+  "value": {
+    "start": "2019-09-13T01:02:03.456789Z",
+    "end": "2019-09-13T02:02:03.456789Z",
+    "value": {
+      "avg": 1.2
+    }
+  }
+}

pkg/tsdb/azuremonitor/test-data/applicationinsights/4-application-insights-response-metrics-no-segment.json

@@ -0,0 +1,23 @@
+{
+  "value": {
+    "start": "2019-09-13T01:02:03.456789Z",
+    "end": "2019-09-13T03:02:03.456789Z",
+    "interval": "PT1H",
+    "segments": [
+      {
+        "start": "2019-09-13T01:02:03.456789Z",
+        "end": "2019-09-13T02:02:03.456789Z",
+        "value": {
+          "avg": 1
+        }
+      },
+      {
+        "start": "2019-09-13T02:02:03.456789Z",
+        "end": "2019-09-13T03:02:03.456789Z",
+        "value": {
+          "avg": 2
+        }
+      }
+    ]
+  }
+}

pkg/tsdb/azuremonitor/test-data/applicationinsights/4-application-insights-response-metrics-segmented.json

@@ -0,0 +1,45 @@
+{
+  "value": {
+    "start": "2019-09-13T01:02:03.456789Z",
+    "end": "2019-09-13T03:02:03.456789Z",
+    "interval": "PT1H",
+    "segments": [
+      {
+        "start": "2019-09-13T01:02:03.456789Z",
+        "end": "2019-09-13T02:02:03.456789Z",
+        "segments": [
+          {
+            "value": {
+              "avg": 1
+            },
+            "blob": "a"
+          },
+          {
+            "value": {
+              "avg": 3
+            },
+            "blob": "b"
+          }
+        ]
+      },
+      {
+        "start": "2019-09-13T02:02:03.456789Z",
+        "end": "2019-09-13T03:02:03.456789Z",
+        "segments": [
+          {
+            "value": {
+              "avg": 2
+            },
+            "blob": "a"
+          },
+          {
+            "value": {
+              "avg": 4
+            },
+            "blob": "b"
+          }
+        ]
+      }
+    ]
+  }
+}