Add govspeak support for finder summary

Introduce new schema structures for finder summaries. Specialist finder summaries are now converted to GovSpeak. In order to send GovSpeak the schema structure will have to match multiple content type definitions, but other finders such as licence finder will still be sending a string summary. We need to support both.

content_schemas/dist/formats/finder/frontend/schema.json

@@ -663,6 +663,9 @@
         },
         {
           "type": "null"
+        },
+        {
+          "type": "string"
         }
       ]
     },

content_schemas/dist/formats/finder/notification/schema.json

@@ -763,6 +763,9 @@
         },
         {
           "type": "null"
+        },
+        {
+          "$ref": "#/definitions/multiple_content_types"
         }
       ]
     },
@@ -1023,6 +1026,25 @@
         "zh-tw"
       ]
     },
+    "multiple_content_types": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "required": [
+          "content_type",
+          "content"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "content": {
+            "type": "string"
+          },
+          "content_type": {
+            "type": "string"
+          }
+        }
+      }
+    },
     "payload_version": {
       "description": "Counter to indicate when the payload was generated",
       "type": "integer"

content_schemas/dist/formats/finder/publisher_v2/schema.json

@@ -551,6 +551,9 @@
         },
         {
           "type": "null"
+        },
+        {
+          "$ref": "#/definitions/multiple_content_types"
         }
       ]
     },
@@ -672,6 +675,25 @@
         "zh-tw"
       ]
     },
+    "multiple_content_types": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "required": [
+          "content_type",
+          "content"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "content": {
+            "type": "string"
+          },
+          "content_type": {
+            "type": "string"
+          }
+        }
+      }
+    },
     "public_updated_at": {
       "description": "When the content was last significantly changed (a major update). Shown to users.  Automatically determined by the publishing-api, unless overridden by the publishing application.",
       "type": "string",

content_schemas/formats/shared/definitions/finder.jsonnet

@@ -288,6 +288,9 @@
       {
         type: "null",
       },
+      {
+        "$ref": "#/definitions/multiple_content_types",
+      },
     ],
   },
   finder_beta: {