add 2D support for picongpu

- some plugins are disabled if we select 2D simulation mode
- 3D config files can used for 2D simulations

supported Plugins:
- png output
- energy fields
- energie electrons/ions
- count particles
- hdf5 + restart
- bin energy electrons/ions

Supported solver:
- Esirkepov all shapes
- Boris particle pusher

**THIS IS A PREVIEW**
~~please do not merge before next week~~