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
