[VS Code] Refactor "Ai Assisted" to "Duo" in settings
Problem to solve
We currently use the term Ai Assisted in VS Code's settings. This terminology is unique to VS Code and is inconsistent with our JetBrains settings. It's also misaligned with how we are moving towards displaying Code Suggestions under the Duo status icon in gitlab#464018 (closed).
As a user I want an extension's settings to use consistent terminology so that I can quickly navigate the settings list by keyword and understand the relationship between specific settings and features.
Proposal
Reword Ai Assisted to Duo in VS Code's settings.
Bonus: Reorder Duo settings to keep them grouped together so they aren't split up by other extension settings.
Further details
Example of current settings
