feat(api): accept rule config block string in playground

Update playground request to take rules as a string and parse
either YAML list or DSL config, with tests and swagger updates.

internal/api/v1/docs/swagger.json

@@ -5125,10 +5125,7 @@
           "$ref": "#/definitions/MockResponse"
         },
         "rules": {
-          "type": "array",
-          "items": {
-            "$ref": "#/definitions/routeApi.RawRule"
-          },
+          "type": "string",
           "x-nullable": false,
           "x-omitempty": false
         }
@@ -6926,28 +6923,6 @@
       "x-nullable": false,
       "x-omitempty": false
     },
-    "routeApi.RawRule": {
-      "type": "object",
-      "properties": {
-        "do": {
-          "type": "string",
-          "x-nullable": false,
-          "x-omitempty": false
-        },
-        "name": {
-          "type": "string",
-          "x-nullable": false,
-          "x-omitempty": false
-        },
-        "on": {
-          "type": "string",
-          "x-nullable": false,
-          "x-omitempty": false
-        }
-      },
-      "x-nullable": false,
-      "x-omitempty": false
-    },
     "routeApi.RoutesByProvider": {
       "type": "object",
       "additionalProperties": {