Fix Paginator dropping results on empty token pages (DECO-27280)

The Paginator stopped iterating at the first empty page even when the
response carried a valid next_page_token, silently dropping results on
later pages. Token-paginated endpoints (e.g. tables().list) can return
empty intermediate pages with a token (UC filters out non-listable items),
so the SDK could under-return — in the reported case it returned 0 tables
where Python returned 23.

Replace the public Paginator constructor with two explicit factories:
  - Paginator.newTokenPagination: iterate until nextPageFn returns null;
    empty pages are skipped, not treated as the end of results.
  - Paginator.newOffsetPagination: stop on the first empty page (offset/
    SCIM/legacy-SQL APIs have no token and rely on this).
The constructor is now private, so every call site must state its strategy.

Regenerated all *API.java list methods to the appropriate factory (token
APIs and clusters/events -> newTokenPagination; offset/SCIM/legacy-SQL ->
newOffsetPagination) via the genkit java template change. Hand-written
APIs updated manually: SharesExtAPI -> newTokenPagination; the SCIM
Users/Groups/ServicePrincipals (and Account* variants) -> newOffsetPagination.

PaginatorTest covers empty leading/intermediate token pages and offset
stop-on-empty. Full SDK recompiled (mvn clean compile, 3902 sources).

Signed-off-by: Hector Castejon Diaz <hector.castejon@databricks.com>

Author: hectorcast-db