Add Abbr tag for Secret Variable Names

Description

please do not truncate long Secret variables names in Settings > CI / CD Settings > Secret variables or at least use the abbr html tag.

<abbr title="MY_TRUNCATED_NAME_WHICH_IS_THIS_LONG_IN_REALITY">MY_TRUNCATED_NAME...</abbr>

example link: https://gitlab.com/group/project/settings/ci_cd

in general the site layout is not that good. having so much space for Protected but truncating such an important thing as the variable name is not a good DX. for protected a simple icon or a x in a column which header uses the abbr tag would be enough

related: gitlab-ce#35893