feat!: list_databases returns an iterator (#4442)

CatalogConnection.list_databases should return an iterator so that users
don't have to manually re-implement pagination. For those who do want
more control over pagination, add num_page_results and page_token to the
Iterator object, and also allow the iterator object to be created at a
specific page token.

docs/src/js/interfaces/ListDatabasesResponse.md

@@ -1,23 +0,0 @@
-[**@lancedb/lancedb**](../README.md) • **Docs**
-
-***
-
-[@lancedb/lancedb](../globals.md) / ListDatabasesResponse
-
-# Interface: ListDatabasesResponse
-
-## Properties
-
-### databases
-
-```ts
-databases: string[];
-```
-
-***
-
-### pageToken?
-
-```ts
-optional pageToken: string;
-```