- Moves AI settings into a new AI section
 - Renames new setting into a `gitlens.ai` namespace and changes it to be an enum for easier selection
 - Updates max characters to be dependent on selected model

- Moves _Copy Remote \* URL_ from _Copy As_ to _Share_
 - Moves _Copy SHA_,  _Copy Message_,  _Copy Relative Path_ from _Copy As_ to root

Co-authored-by: Eric Amodio <eamodio@users.noreply.github.com>

Closes #2252
Closes #2448
Follow-up to 5f95876a97

- Controlled by the `gitlens.graph.experimental.location` setting

- Honors `createBranch` flag for naming the worktree folder
- Falls back to the qualified remote branch name if the branch name already exists
- Always uses the qualified remote branch name via GHPR command