nx release plan against packages without changes should default to 'none'

[jonathanmorley]

The default option (because it is the first) when running nx release plan is major.

Often, changes only affect a subset of packages. It is useful to present that set as the default set of packages to make material (not none) bumps.

[bitfrost]

Also, ideally nx release plan should only default to prompting for the same packages returned as needing plans form nx release plan:check , walking through the rest is painful in a large mono repo