Fabo/affiliate fees keeper

[faboweb]

Closes: #XXX

What is the purpose of the change

Add a description of the overall background and high level changes that this PR introduces

(E.g.: This pull request improves documentation of area A by adding ....

Testing and Verifying

(Please pick one of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added unit test that validates ...
• Added integration tests for end-to-end deployment with ...
• Extended integration test for ...
• Manually verified the change by ...

Documentation and Release Note

• [ ] Does this pull request introduce a new feature or user-facing behavior changes?
• [ ] Changelog entry added to Unreleased section of CHANGELOG.md?

Where is the change documented?

• [ ] Specification (x/{module}/README.md)
• [ ] Osmosis documentation site
• [ ] Code comments?
• [ ] N/A