`malloc` abstraction inside jobs for garbage collection

[jake-is-ESD-protected]

In a recent workshop, it was asked if jescore performs garbage collection on dynamically allocated memory. This is a bit much to ask, but a simpler idea might be feasible: abstract malloc into jes_malloc.

This function or macro could then be used to call malloc and store the resulting pointer. A copy of that is returned to the user. When the job is ended, the pointer is freed. The user does not have to worry about free.

An issue might be the amount of calls. Each call requires a pointer. These have to be stored in the job. It is unclear how many calls a user might need in a job.