crm cluster health uses platform.linux_distribution, dropped in python 3.8

[athos-ribeiro]

scripts/health/collect.py relies on a call to platform.linux_distribution, which has been deprecated since Python 3.5 and was removed on python 3.8 [1].

This results in errors for crm cluster health calls on systems with python >= 3.8.

Until Python 3.7, when platform.linux_distribution was still present and deprecated, the Python docs suggested using distro [3] as an alternative, which could be a solution for this issue. However, distro itself requires python >= 3.6, which could imply losing support for python 3.4 and 3.5 or implementing a fallback logic to use platform.linux_distribution when available.

[1] https://bugs.python.org/issue28167
[2] https://docs.python.org/3.7/library/platform.html#platform.linux_distribution
[3] https://pypi.org/project/distro/

[liangxin1300]

@athos-ribeiro Thanks for pointing this!
To be honest, the content in scripts/health/collect.py seems duplicated a little, comparing with codes in crmsh/report
So here I want to reuse the function get_distro_info from crmsh/report/utillib.py, see c90a4e6
and #883