Allow to rewrite frame generator in python
For now BLISS and Tomo create a custom Lima simulator by using a plugin (slit lima simulator, tomo lima simulator).
The plugin basically override the whole image.
It could be easier to allow to override the simulator method generating the image.
According to Seb, it's as easy as creating a virtual method for this function, including a SIP definition.
This could simplify a lot the lima simulator in BLISS.