In addition to default (system) ssh version, report configured ssh; fix ssh version parsing on Windows

[yarikoptic]

Closes #6728 in the first commit fixing the parsing of a more elaborate version "identifier".

Then two subsequent commits pretty much provide two alternative ways to present 2nd version of ssh -- the one we actually use, which might be not the "system" one, i.e. not the one "first" in the PATH but the one we configure to use since #6553 which is on Windows is the "system" one, i.e. installed system wide and not in conda. (but not necessarily reported as cmd:system-ssh).

So here is how it looks for me on windows ATM:

(datalad) C:\Users\DataLad\PycharmProjects\datalad>datalad wtf -S dependencies
# WTF
## dependencies
  - annexremote: 1.2.1
  - boto: 2.49.0
  - cmd:7z: 9.20
  - cmd:annex: 8.20201008-g3be4731
  - cmd:bundled-git: UNKNOWN
  - cmd:git: 2.34.1.windows.1
  - cmd:ssh: 8.1p1
  - cmd:system-git: 2.34.1.windows.1
  - cmd:system-ssh: 8.8p1
  - exifread: 2.1.2
  - humanize: 3.1.0
  - iso8601: 0.1.13
  - keyring: 21.4.0
  - keyrings.alt: 3.1
  - msgpack: 1.0.0
  - mutagen: 1.41.1
  - platformdirs: 2.5.1
  - requests: 2.24.0

and on maint it is

(datalad) C:\Users\DataLad\PycharmProjects\datalad>datalad wtf -S dependencies | grep ssh
  - cmd:system-ssh: 8.8p1

since

(datalad) C:\Users\DataLad\PycharmProjects\datalad>ssh -V
OpenSSH_8.8p1, OpenSSL 1.1.1l  24 Aug 2021

(datalad) C:\Users\DataLad\PycharmProjects\datalad>C:\WINDOWS\System32\OpenSSH\ssh.exe -V
OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2

and if I move the "default" ssh aside I get that for for the version @adswa observed in #6617 (comment) :

(datalad) C:\Users\DataLad\PycharmProjects\datalad>mv C:\Users\DataLad\miniconda3\envs\datalad\Library\usr\bin\ssh.exe  C:\Users\DataLad\miniconda3\envs\datalad\Library\usr\bin\ssh.exe_aside

(datalad) C:\Users\DataLad\PycharmProjects\datalad>ssh -V
OpenSSH_for_Windows_8.1p1, LibreSSL 3.0.2

(datalad) C:\Users\DataLad\PycharmProjects\datalad>datalad wtf -S dependencies | grep ssh
  - cmd:system-ssh: for

[adswa]

thanks for spotting that! makes sense to me.

[github-actions]

🚀 PR was released in 0.16.5 🚀