TUI v0.1

build a TUI binary for ent which mirrors the CLI functionality

- [ ] issues list (88d5111fd6e59802d0b839ff1fd6bf71)
    - [ ] filtering(?)
- [x] show issue preview
- [x] show issue detail
- [ ] commands
    - [ ] new ($EDITOR)
    - [ ] edit ($EDITOR)
    - [ ] comment ($EDITOR)
    - [ ] state