chore: move collections sync system to platform (#2940)

packages/hoppscotch-common/src/platform/collections.ts

@@ -0,0 +1,3 @@
+export type CollectionsPlatformDef = {
+  initCollectionsSync: () => void
+}

packages/hoppscotch-common/src/platform/index.ts

@@ -1,12 +1,14 @@
 import { AuthPlatformDef } from "./auth"
 import { UIPlatformDef } from "./ui"
 import { EnvironmentsPlatformDef } from "./environments"
+import { CollectionsPlatformDef } from "./collections"
 
 export type PlatformDef = {
   ui?: UIPlatformDef
   auth: AuthPlatformDef
   sync: {
     environments: EnvironmentsPlatformDef
+    collections: CollectionsPlatformDef
   }
 }