feat(server): random assets API (#4184)

* feat(server): get random assets API

* Fix tests

* Use correct validation annotation

* Fix offset use in query

* Update API specs

* Fix typo

* Random assets e2e tests

* Improve e2e tests

server/immich-openapi-specs.json

@@ -1510,6 +1510,50 @@
         ]
       }
     },
+    "/asset/random": {
+      "get": {
+        "operationId": "getRandom",
+        "parameters": [
+          {
+            "name": "count",
+            "required": false,
+            "in": "query",
+            "schema": {
+              "type": "number"
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "content": {
+              "application/json": {
+                "schema": {
+                  "items": {
+                    "$ref": "#/components/schemas/AssetResponseDto"
+                  },
+                  "type": "array"
+                }
+              }
+            },
+            "description": ""
+          }
+        },
+        "security": [
+          {
+            "bearer": []
+          },
+          {
+            "cookie": []
+          },
+          {
+            "api_key": []
+          }
+        ],
+        "tags": [
+          "Asset"
+        ]
+      }
+    },
     "/asset/search": {
       "post": {
         "operationId": "searchAsset",