fix: add type extensions to postman-collection types

packages/hoppscotch-app/types/pm-coll-exts.d.ts

@@ -0,0 +1,21 @@
+import "postman-collection"
+
+/*
+  There are some small mismatches in some types that the 'postman-collection'
+  package provides (come on guys ;) ). These type definitions append extra
+  information which is present in the runtime values of the types
+*/
+
+type PMRawLanguage = "text" | "javascript" | "json" | "html" | "xml"
+
+declare module "postman-collection" {
+  interface RequestBody {
+    // Options is not well-defined by the schema, so we are treating everything as optional for runtime safety.
+    // See: https://schema.postman.com/collection/json/v2.1.0/draft-04/collection.json
+    options?: {
+      raw?: {
+        language?: PMRawLanguage
+      }
+    }
+  }
+}