cli: fix showing active state for `nmcli con show` with fields

With "connection.multi-connect", a profile can be activated multiple
times on a device with `nmcli connection show`. Also, a profile may be
in the process of deactivating on one device, while activating on
another one. So, in general it's possible that `nmcli connection show`
lists the same profile on multiple lines (reflecting their multiple
activation states).

If the user requests no fields that are part of the activation state,
then the active connections are ignored. For example with `nmcli
-f UUID,NAME connection show`. In that case, each profile is listed only
once.

On the other hand, with `nmcli -g UUID,NAME,DEVICE connection show` the
user again requested also to see the activation state, and a profile can
appear multiple times.

To handle that, we need to consider which fields were requested.

There was a bug where the "ACTIVE" field was not treated as part of the
activation state. That results in `nmcli -f UUID,NAME,ACTIVE connection
show` always returning "no". Fix that.

Fixes: a1b25a47 ('cli: rework printing of `nmcli connection` for multiple active connections')
21 jobs for th/cli-fix-con-show-active-field in 38 minutes and 29 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #4912588
checkpatch

00:01:58

manual #4912596
allowed to fail manual
t_centos:7.5.1804
manual #4912597
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t_centos:7.6.1810
manual #4912598
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t_centos:7.7.1908
manual #4912599
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t_centos:7.8.2003
manual #4912600
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t_centos:8.1.1911
manual #4912606
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t_debian:10
manual #4912605
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t_debian:9
manual #4912608
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t_debian:sid
manual #4912607
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t_debian:testing
manual #4912589
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t_fedora:28
manual #4912590
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t_fedora:29
manual #4912591
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t_fedora:30
manual #4912592
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t_fedora:31
passed #4912593
t_fedora:32

00:38:29

manual #4912594
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t_fedora:33
manual #4912595
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t_fedora:rawhide
manual #4912601
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t_ubuntu:16.04
manual #4912602
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t_ubuntu:18.04
manual #4912604
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t_ubuntu:devel
manual #4912603
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t_ubuntu:rolling