Generate GRADEs together. Show only wrong GRADEs, like B,C or NONE

[phracek]

This pull request generates GRADEs across all RHEL8, RHEL9, and RHEL10 images.

Only wrong GRADEs are shown.

See mail example:

Nightly report for container grades for RHEL8 is:
ubi8/nodejs-20 [B] days until grade C!
ubi8/perl-526 [C] days since grade C!
rhel8/perl-526 [C] days since grade C!
ubi8/perl-532 [C] days since grade C!
rhel8/perl-532 [C] days since grade C!
The rest of images are in grade A.

Nightly report for container grades for RHEL9 is:
ubi9/php-80 [B] days until grade C!
rhel9/php-80 [B] days until grade C!
ubi9/php-81 [B] days until grade C!
rhel9/php-81 [B] days until grade C!
ubi9/php-82 [B] days until grade C!
rhel9/php-82 [B] days until grade C!
ubi9/python-39 [B] days until grade C!
rhel9/python-39 [B] days until grade C!
ubi9/python-312 [B] days until grade C!
rhel9/python-312 [B] days until grade C!
ubi9/perl-532 [B] days until grade C!
rhel9/perl-532 [B] days until grade C!
ubi9/ruby-30 [B] days until grade C!
rhel9/ruby-30 [B] days until grade C!
ubi9/ruby-33 [B] days until grade C!
rhel9/ruby-33 [B] days until grade C!
The rest of images are in grade A.

Nightly report for container grades for RHEL10 is:
All images for RHEL10 are in grade A.

The rest of images are in grade A.