Merge branch '421698-extract-format-iso-8601-date-function-to-datetime-utility' into 'master'

Extract formatIso8601Date function to datetime utility

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/180530



Merged-by: Florie Guibert <fguibert@gitlab.com>
Approved-by: Nataliia Radina <nradina@gitlab.com>
Approved-by: Florie Guibert <fguibert@gitlab.com>
Reviewed-by: Ammar Alakkad <aalakkad@gitlab.com>
Co-authored-by: Ammar Alakkad <am.alakkad@gmail.com>