implement zram support

[smira]

See also #11589

Support zram as well (https://docs.kernel.org/admin-guide/blockdev/zram.html).

What we need:

• a new volume type
• on volume provisioning, create respective sysfs values and wait for them to propagate (using KernelParamSpec/KernelParamStatus), run "mkswap" (same as disk swap)
• when being mounted, use same swapon/swapoff
• on volume destroying, remove sysfs values, and instead write "reset" value, wait for propagation, remove it