Add tests for particle_system

[rwkay]

Description

We don't have tests for particle_system functions to ensure that they are working consistently

Steps To The Task

A test to see if reference names are correct.
A test to see if part_system_create variants correctly create a part_system.
A test to see if particle systems made with a persistent option are keep in another room (it check if a part system made without a persisten tag are keeping in memory too)
And various test with part_system_get_info to see if the information returned are in line with what the documentation tells what it should return.

Outcome

We should have tests that exercise the particle_system functions..