Generify get/post map with Map

[Katsute]

Prerequisites

If all checks are not passed then the request will be closed

• I have checked that no other similar feature request already exists
• The feature request makes sense for the project

Proposal

Describe the feature that should be added
Convert HashMap parameters to Map parameters

Reasoning

Explain why this feature should be added
Better access to unmodifable, also hashmap param is not needed