external knowledge api (#8913)

Co-authored-by: Yi <yxiaoisme@gmail.com>

web/app/components/datasets/external-api/declarations.ts

@@ -0,0 +1,16 @@
+export type CreateExternalAPIReq = {
+  name: string
+  settings: {
+    endpoint: string
+    api_key: string
+  }
+}
+
+export type FormSchema = {
+  variable: string
+  type: 'text' | 'secret'
+  label: {
+    [key: string]: string
+  }
+  required: boolean
+}