Add a page_size when listing the endpoints in the API

Describe the MR

Change the default page_size when listing the ProbeConfiguration from the API (a.k.a. Endpoint in watch)

Why was this MR needed?

To push the problem for later. We should loop until next_page_token, but we'll do that later.

Extra-care points?

Does this MR meet the acceptance criteria?

• Documentation created/updated
• CHANGELOG updated
• Unit Tests added/updated

What are the relevant issue numbers?

License and Developer Certificate of Origin

• By contributing to Pantomath SAS, You accept and agree to the following terms and conditions for Your present and future Contributions submitted to Pantomath SAS. Except for the license granted herein to Pantomath SAS and recipients of software distributed by Pantomath SAS, You reserve all right, title, and interest in and to Your Contributions. All Contributions are subject to the following Developer Certificate of Origin and License terms.