BucketsAPI::findBuckets() is limited to 20 by default

__Steps to reproduce:__
List the minimal actions needed to reproduce the behavior.

1. have an influxdb2 instance with more than 20 buckets
2. call BucketsApi::findBuckets()

__Expected behavior:__
The API returns all buckets

__Actual behavior:__
The API returns at most 20 buckets

__Specifications:__
- Client Version: com.influxdb:influxdb-client-java:6.9.0
- InfluxDB Version: 2.7
- JDK Version: Eclipse Adoptium jdk-17.0.6.10-hotspot
- Platform: docker / alpine-linux

Start at the BucketsAPI::findBuckets() entry point and reproduce the behavior against an InfluxDB 2 instance containing more than 20 buckets. Check how the request limits results, then verify that the API returns all buckets rather than at most 20; the payload does not name a source file or test.

Written by the indexing model from the issue text.