Fixes #37287 - Iterate on hashes when both key and value are used

This replaces the `hash.keys.each { |k| hash[k] }` and `hash.keys.sort`
patterns with `hash.each { |k, v| }` where it makes sense. This avoids
doing hash lookups when you already know the value anyway.

Fixes #37002 - Add pagelet anchor for user and usergroup tabs

This feature allows plugins to add pagelets for the users/usergroups
edit page.

Refs #37010 - Ensure correct yaml for netplan

The introduced safe operator returns nil instead of false, but the
snippet expects true/false.

Refs #37034 - Fix ERB syntax for comments

Co-authored-by: Markus Bucher <bucher@atix.de>

Fixes #37167 - Subscription entitlement report template

Refs #36574 - Avoid patching Fastgettext

The code defines an additional method on Fastgettext but there's no
reason to do so. It can just as well define a method on itself.

Refs #37034 - Use apt-key add on Ubuntu 16.04

• On Ubuntu 16.04, which is supported by Canonical until 2026, you
  cannot place a GPG public key in "/etc/apt/trusted.gpg.d/" and use it
  to verify the signature of "Release" files.
• EoL Ubuntu 16.04: https://ubuntu.com/16-04...

Fixes #37011 - Apply latest Ubuntu Autoinstall userdata changes

• Add explicit fallback for offline installation
• Replace deprecated lock-passwd with lock_passwd
• Remove empty ssh keys array if none provided

Fixes #37193 - trap ERR not supported on dash

Fixes #36502 - iPXE Discovery Only Works on net0