Environment Jagged Array Support (CSR)

[Robadob]

Fujitsu has exposed a need for jagged arrays to represent data accessible to agents, which doesn't cleanly fit into a fixed length environment macro property or agent variable array.

In this case of Fujitsu, this was for lane shape data and vehicle routes. Both which could vary from a length of 2 to something without a clear upper bound.

We've handled this by implementing a bespoke CSR for each case, accessed via a device symbol. This is suitable for advanced C++ API users, but would leave certain modelling techniques out of reach of Python users.