Library Elements API GET by name returns array (#44743)

* Library Elements API GET by name returns array

Making a GET request to the Library Elements HTTP API `api/library-elements/name/:name` will return an **array** of Library Element objects, but the documentation says it will return a Library Element object.

Example cURL POST request:
`curl -X POST -H "Content-Type: application/json" -H "Authorization: Bearer XXXXXXXXXXX" -d @request.json "https://my.grafana.net/api/library-elements/"`

request.json
```json
{
  "model": {},
  "kind": 1,
  "name": "testing description3",
  "uid": "basic3",
  "id": 12345,
  "version": 2
}
```

Example cURL GET request:
`curl -X GET -H "Content-Type: application/json" -H "Authorization: Bearer XXXXXXXX" -d @request "https://my/api/library-elements/name/testing description3"`

Example response:
```json
{
    "result": [
        {
            . . .
        }
    ]
}
```

* Library Elements API fix bracket spacing

docs/sources/http_api/library_element.md

@@ -176,35 +176,37 @@ HTTP/1.1 200
 Content-Type: application/json
 
 {
-    "result": {
-      "id": 25,
-      "orgId": 1,
-      "folderId": 0,
-      "uid": "V--OrYHnz",
-      "name": "API docs Example",
-      "kind": 1,
-      "type": "text",
-      "description": "",
-      "model": {...},
-      "version": 1,
-      "meta": {
-          "folderName": "General",
-          "folderUid": "",
-          "connectedDashboards": 1,
-          "created": "2021-09-27T09:56:17+02:00",
-          "updated": "2021-09-27T09:56:17+02:00",
-          "createdBy": {
-              "id": 1,
-              "name": "admin",
-              "avatarUrl": "/avatar/46d229b033af06a191ff2267bca9ae56"
-          },
-          "updatedBy": {
-              "id": 1,
-              "name": "admin",
-              "avatarUrl": "/avatar/46d229b033af06a191ff2267bca9ae56"
-          }
-      }
-   }
+    "result": [
+        {
+            "id": 25,
+            "orgId": 1,
+            "folderId": 0,
+            "uid": "V--OrYHnz",
+            "name": "API docs Example",
+            "kind": 1,
+            "type": "text",
+            "description": "",
+            "model": {...},
+            "version": 1,
+            "meta": {
+                "folderName": "General",
+                "folderUid": "",
+                "connectedDashboards": 1,
+                "created": "2021-09-27T09:56:17+02:00",
+                "updated": "2021-09-27T09:56:17+02:00",
+                "createdBy": {
+                    "id": 1,
+                    "name": "admin",
+                    "avatarUrl": "/avatar/46d229b033af06a191ff2267bca9ae56"
+                },
+                "updatedBy": {
+                    "id": 1,
+                    "name": "admin",
+                    "avatarUrl": "/avatar/46d229b033af06a191ff2267bca9ae56"
+                }
+            }
+        }
+    ]
 }
 ```