Expressions: Fixes the issue showing expressions editor (#62510)

* Use suggested value for uid

* update the snapshot

* use __expr__

* replace all -100 with __expr__

* update snapshot

* more changes

* revert redundant change

* Use expr.DatasourceUID where it's possible

* generate files

pkg/services/ngalert/api/tooling/api.json

@@ -99,7 +99,7 @@
   "AlertQuery": {
    "properties": {
     "datasourceUid": {
-     "description": "Grafana data source unique identifier; it should be '-100' for a Server Side Expression operation.",
+     "description": "Grafana data source unique identifier; it should be '__expr__' for a Server Side Expression operation.",
      "type": "string"
     },
     "model": {
@@ -2212,7 +2212,7 @@
     "data": {
      "example": [
       {
-       "datasourceUid": "-100",
+       "datasourceUid": "__expr__",
        "model": {
         "conditions": [
          {
@@ -3284,7 +3284,6 @@
    "type": "object"
   },
   "URL": {
-   "description": "The general form represented is:\n\n[scheme:][//[userinfo@]host][/]path[?query][#fragment]\n\nURLs that do not start with a slash after the scheme are interpreted as:\n\nscheme:opaque[?query][#fragment]\n\nNote that the Path field is stored in decoded form: /%47%6f%2f becomes /Go/.\nA consequence is that it is impossible to tell which slashes in the Path were\nslashes in the raw URL and which were %2f. This distinction is rarely important,\nbut when it is, the code should use RawPath, an optional field which only gets\nset if the default encoding is different from Path.\n\nURL's String method uses the EscapedPath method to obtain the path. See the\nEscapedPath method for more details.",
    "properties": {
     "ForceQuery": {
      "type": "boolean"
@@ -3320,7 +3319,7 @@
      "$ref": "#/definitions/Userinfo"
     }
    },
-   "title": "A URL represents a parsed URL (technically, a URI reference).",
+   "title": "URL is a custom URL type that allows validation at configuration load time.",
    "type": "object"
   },
   "Userinfo": {
@@ -3497,6 +3496,7 @@
    "type": "object"
   },
   "alertGroup": {
+   "description": "AlertGroup alert group",
    "properties": {
     "alerts": {
      "description": "alerts",
@@ -3624,6 +3624,7 @@
    "type": "object"
   },
   "gettableAlert": {
+   "description": "GettableAlert gettable alert",
    "properties": {
     "annotations": {
      "$ref": "#/definitions/labelSet"
@@ -3685,7 +3686,6 @@
    "type": "array"
   },
   "gettableSilence": {
-   "description": "GettableSilence gettable silence",
    "properties": {
     "comment": {
      "description": "comment",
@@ -3734,6 +3734,7 @@
    "type": "object"
   },
   "gettableSilences": {
+   "description": "GettableSilences gettable silences",
    "items": {
     "$ref": "#/definitions/gettableSilence"
    },
@@ -4854,4 +4855,4 @@
   }
  },
  "swagger": "2.0"
-}
+}