config: simplify no-auto-default list handling and sort entries

- don't let no_auto_default_from_file() do any preprocessing of
  the lines that it reads. It merely splits the lines at '\n'
  and utf8safe-unescapes them.
  This was previously duplicated also by NMConfigData's property
  setter. We don't need to do it twice.

- sort the lines. This makes the entire handling O(n*ln(n)) instead
  of O(n^2). Also, sorting effectively normalizes the content, and
  it's desirable to have one true representation of what we write.
18 jobs for th/no-auto-default-by-ifname in 67 minutes and 16 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #432514
allowed to fail
checkpatch

00:01:36

manual #432519
allowed to fail manual
t_centos:7.5.1804
passed #436756
t_centos:7.6.1810

00:25:32

passed #432526
t_debian:10

00:30:27

passed #432525
t_debian:9

00:21:30

passed #432528
t_debian:sid

00:21:06

manual #432527
allowed to fail manual
t_debian:testing
passed #432515
t_fedora:28

00:27:51

passed #432516
t_fedora:29

00:30:30

passed #432517
t_fedora:30

00:32:05

manual #432518
allowed to fail manual
t_fedora:rawhide
passed #432521
t_ubuntu:16.04

00:30:34

passed #432522
t_ubuntu:18.04

00:21:30

manual #432524
allowed to fail manual
t_ubuntu:devel
manual #432523
allowed to fail manual
t_ubuntu:rolling
failed #432520
t_centos:7.6.1810

00:29:20

 
  External
failed NetworkManager test verification

failed NetworkManager test verification

06:50:23