Merge pull request #324 from billygoo/billy-1.2.0

Pull Request issue #318, #319
fix : 
- 에디터에 포커스가 가지 않는 오류수정
- Fixed an error that focus does not move to the editor.
https://github.com/hangum/TadpoleForDBTools/issues/319

enhancement : 
- Add connection dialog
- Add table, column list
https://github.com/hangum/TadpoleForDBTools/issues/300