GUI for Pidgeon Render Farm

[BlenderDefender]

Add a GUI to Pidgeon Render Farm, that allows to use PRF from outside Blender without having to learn how to use it from the console.

### Tasks
- [ ] https://github.com/PidgeonTools/PidgeonRenderFarm/issues/31
- [ ] https://github.com/PidgeonTools/PidgeonRenderFarm/issues/32
- [ ] https://github.com/PidgeonTools/PidgeonRenderFarm/issues/33
- [ ] https://github.com/PidgeonTools/PidgeonRenderFarm/issues/34
- [ ] https://github.com/PidgeonTools/PidgeonRenderFarm/issues/35