bsdinstall: Improve pkgbase handling for jails

Add a new --jail option to the pkgbase script which installs
jail-specific set variants if they exist:

* "minimal" is replaced with "minimal-jail"

* A kernel is not installed.

* For sets shown in the component selection dialogue, only show the
  appropriate variant (jail or non-jail) for the target.

Modify the jail script to pass --jail to the pkgbase script.

Remove the redundant --no-kernel option, which was added in 15.0 and
was only used to install jails.

MFC after:	3000ms
Reviewed by:	ifreund_freebsdfoundation.org
Sponsored by:	https://www.patreon.com/bsdivy
Differential Revision:	https://reviews.freebsd.org/D52829

0 files changed, 0 insertions, 0 deletions