* feat(goctl): supports api multi-level importing Resolves: #1744 * fix(goctl): import-cycle, etc. import-cycle will not be allowed e.g., a.api -> b.api -> a.api regular multiple-import will be allowed e.g., a.api -> b.api -> c.api -> c.api * refactor(goctl): adds comments to exported var * fix(goctl): typo in a comment