#5157902 Color Schemes: Add Aquatic and hide Ocean

The name of a new color scheme.

This is a phase one of #47256 (comment). Please refer to the plan to understand the scope of this PR.

Changes proposed in this Pull Request

• add aquatic color scheme (uses exact same colors as ocean)
• add temporary code in the color scheme picker to pretend “ocean” is “aquatic”

I know what’s the usual reaction when people see temporary code. I’ll personally make sure it will be followed upon 🙂

Testing instructions

• set your account to use Ocean (either on local master branch or in prod https://wordpress.com/me/account)
• boot this PR
• confirm you can still see dark blue colors of “ocean” in the local UI
• navigate to /me/account on this branch and confirm the UI shows “aquatic” as the active scheme

Phase one of #47256