Move Code Quality to Static Analysis

Why is this change being made?

As per https://gitlab.com/gitlab-com/Product/-/issues/2426, we are moving Code Quality to Secure in the Static analysis group. This updates stages.yml and categories.yml as well as relocates the direction page.

This puts GitLab in alignment with the industry's trend of SAST expanding to include Code Quality. This change also optimizing our delivery of these categories as Code Quality leverages some SAST security scanners today and will more as it matures.

closes https://gitlab.com/gitlab-com/Product/-/issues/2426

Approvals

Merge requests with changes to stages and groups and significant changes to categories need to be created, approved, and/or merged by each of the below:

• Chief Product Officer - @sfwgitlab
• VP of Product - @adawar
• Senior Director of Product Management, Dev & Sec - @david
• Senior Director of Product Management, Ops - @kencjohnston
• Director of Engineering, Sec - @tstadelhofer
• Director of Engineering, Ops - @sgoldstein
• Director of Product Design - @vkarnes
• CEO - @sytses

The following people need to be on the merge request so they stay informed:

• Chief Technology Officer @edjdev
• Vice President of Development @clefelhocz1
• Director of Quality @meks
• Vice President of User Experience @clenneville
• The Product Marketing Manager relevant to the stage group(s)