Migrate margin utilities to GitLab UI ones
Migrates margin utils to their GitLab UI equivalents.
Note:
design.gitlab.com
and GitLab UI's utilities are aligned up to the 7th scale. Upwards,m-*-8
corresponds to GitLab UI's 9th scale andm-*-9
corresponds to the 11th scale.
Edited by Paul Gascou-Vaillancourt