`brev create` and `brev search` flags for # of processors and amount of memory are confusing and inconsistent

[brycelelbach]

The flags for specifying # of CPUs/GPUs and amount of memory have vague and ambiguous spellings and gaps:

• --min-vcpu: "v" means "virtual". Minimum number of CPUs.
• --min-vram: Memory per GPU. "v" means "video" (aka GPU).
• --min-total-vram: Total GPU memory.
• --min-ram: Total CPU memory.
• Can't specify the number of GPUs - there's no --min-gpus

Suggestion:

• --min-cpus: Minimum number of CPUs.
• --min-per-cpu-mem: Minimum total CPU memory.
• --min-total-cpu-mem: Minimum total CPU memory.
• --min-gpus: Minimum number of GPUs.
• --min-per-gpu-mem: Minimum per-GPU memory.
• --min-total-gpu-mem: Minimum total GPU memory.
• Keep the old flags around for compat, but deprecate them and leave them out of --help.