Fix MR Selection, Go Code Refactor (#358)

refactor: Refactors the Go codebase into a more modular and idiomatic approach
fix: require selection of specific MR when there are multiple targets for a given source branch
feat: Allows for the passing of Gitlab's filter options when choosing an MR, improves MR selection
feat: API to choose an MR from a list based on the provided username's involvement as an assignee/reviewer/author

This is a #MINOR release

.github/workflows/go.yaml

@@ -19,6 +19,7 @@ jobs:
         with:
           version: v1.54
           only-new-issues: true
+          skip-cache: true
   go_test:
     name: Test Go 🧪 
     needs: [go_lint]