Refactor fetch deployment mod definitions axios call to use RTK Query

[johnnymetz]

User Story

As a frontend developer, I an API call to fetch deployment mod definitions to use RTK, so we get the RTK query benefits (caching) and consistency with the rest of the codebase

Motivation

RTK query is better than using axios directly

Acceptance Criteria

• Update this axios call to use RTK query:
• Note, we need to keep the fetchDeploymentModDefinitions function because it's used in the background script, see deploymentUpdater.ts (unless we somehow figure out how to use RTK query in the bg script)