CCOL-2441: Allow custom publishing batch size per producer

[ariana-flipp]

Pull Request Template

Description

Enabled the ability to configure max_batch_size on a per-producer level instead of hard-coded limit of 500. The global setting is still set to 500 by default.

Fixes CCOL-2441

Type of change

• [x] New feature (non-breaking change which adds functionality)
• [x] This change requires a documentation update

How Has This Been Tested?

Added specs

Checklist:

• [ ] My code follows the style guidelines of this project
• [ ] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have added a line in the CHANGELOG describing this change, under the UNRELEASED heading
• [ ] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

[dorner]

LGTM!