Visual inconsistencies in incident sidebar

Summary

The spacing on incident sidebar items is different in each section:

Much of these inconsistencies were fixed already as part off !61650 (merged). But, we'll still need to go in and fix the incident-specific sidebar items, such as severity.

Steps to reproduce

View any incident. For example, this one.

Example Project

What is the current bug behavior?

Spacing between headers and selections is not consistent.

What is the expected correct behavior?

Spacing between the headers and selections should be consistent in all sections.

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes