Add option to alter the maximum memory the JVM can use when launch the COE

[maxs-rose]

It is theoretically possible for a co-simulation to require more memory than is given to the JVM by default. With higher thread counts for DSE, this can also become a problem.

When launching the coe would need to do java -Xmx1024 -jar coe.jar to specify the max memory usage.

Could be a slider next to the launch button for the coe or something