Add --format option to multipass version command

[cjp256]

Describe the bug
Multipass sometimes logs unrelated messages to stdout. When parsing stdout information, this can lead to undesirable behavior.

To Reproduce
Install multipass 1.5 for Windows.

Run multipass version

How, and what happened?

>multipass version 2>stderr.txt
multipass  1.5.0+win
multipassd 1.5.0+win

###########################################################################################
New Multipass 1.6.2 release
Now with bridged networking support

Go here for more information: https://github.com/CanonicalLtd/multipass/releases/tag/v1.6.2
###########################################################################################

Expected behavior
The extra outputs should be logged to stderr to allow for more reliable parsing of stdout.

[Saviq]

I'd say we should have a --format for multipass version instead, so you can safely parse that.

[cjp256]

I'd say we should have a --format for multipass version instead, so you can safely parse that.

Even better 👍

[surahman]

With respect to #2077 :
I made the modifications to include the --format flag and it will only be recognised in conjunction with the -V and --version cmdl flags. Corrected a typo with a missing quote in the help info string.

[Saviq]

Fixed in #2077