Match "zfs list, send, receive" arguments in the appropriate context

[bellhyve]

To simplify flag passing, we'll make the argument parser pass most zfs list, send, and receive flags. There are a few conflicts that will need to be documented.

[bellhyve]

Added zelta sendopts and load them into a variable called VALID_SEND_OPTS. I need to parse out options but need to watch out for - versus -- options.

[bellhyve]

zelta sendopts is too fiddly but I found a better solution. Targeting Zelta 1.2 Q2 2026.

[bellhyve]

This is going to be a bit trickier. zfs create -u doesn't work on illumos and the output can be pretty noisy.