Bump up maximum VM memory size to 1024 GiB

[askfongjojo]

The maximum is raised to 1024 GiB with the fixes in oxidecomputer/omicron#7918. Once the related PRs have landed, please change the web console validations to match with the new maximum size.

[david-crespo]

Omicron work is in oxidecomputer/omicron#8160. Looks like it might end up being 1.5 TiB instead of 1 TiB.

[askfongjojo]

Yes you are right. @iximeow also pointed out that we can allow bigger VMs. We are going to confirm that 1.5T also works well enough.

One thing I noticed while testing is that the time it takes to stop a running VM is substantially longer. The console status auto-fresh sometimes timed out for me (i.e., the state stayed at "Stopping" but changed to "Stopped" immediately upon manual refresh).

[iximeow]

One thing I noticed while testing is that the time it takes to stop a running VM is substantially longer.

this should be substantially improved as of yesterday as the fix for http://illumos.org/issues/17414 is now in stlouis