Rename Memory group to Application Performance group

Why is this change being made?

This MR is to change the Memory group to the Application Performance group. Please see #13714 (closed) for approvals.

Approvals

• VP of Product - @david
• Enablement Director of Product - @joshlambert
• Enablement Director of Engineering - @cdu1
• Director of Product Design - @vkarnes

Informed

• CTO (Eric)
• VP Product (David)
• VP Development (Christopher)
• VP Infrastructure (Steve)
• VP Quality (Mek)
• Engineering Productivity
• Product Marketing Manager

After Approvals and Merge

• Create an issue in the triage-ops project to update GitLab Bot automation
• Mention the product group Technical Writer to update the documentation metadata
• Share MR in #product, #development, and relevant #s_, #g_, and #f_ slack channels