Naming is confusing: find_neighbors

https://github.com/googleapis/python-aiplatform/blob/e3a87f04abf013341fe4f655b96405e27228ffdb/google/cloud/aiplatform/matching_engine/matching_engine_index_endpoint.py#L952

There is already a match method (I wrote this integration around a year ago). As I understand, `find_neighbors` is the public version of the match method.

This is quite confusing. Consider:
1. Combining find_neighbors into the match method
2. Calling find_neighbors `match_public` to show that they are related.