Crucible needs a reliability in the face of resource constraints tests

[leftwo]

From the 2/6/23 storage meeting, we discussed having a tests to set of tests that verify crucible
behaves with respect and honor in the face of resource constraints.

Some ideas that were discussed:

• A fault injection layer below crucible to simulate errors in system calls.
• Creating crucible on a VM or zone, and then limiting that VM/zones memory.
• Creating an external program that, after crucible is running, will allocate all or most available memory.