Build a container image based on builder image to be run on CorteXlab

[marcusmueller]

[ Organization Owners: Assign to @marcusmueller , click the ··· next to the list item below, convert that to a sub-issue and remove this line, please ]

We should make it easy for people to use GR4.

To that end, an image with GR4 readily built inside is important.

Subtask:

• [ ] create binary that takes flow graph definition file and instantiates the GR4 FG, runs it