## Description
Fixes#39376
Add individual FoldAtLevel1-9 actions so users can find fold commands in
the command palette while keeping existing keybindings.
Migrating user keymaps is necessary to have the keybinds show in the command palette.
Closes#39376
### Changes
- `crates/editor/src/actions.rs` - Added FoldAtLevel1-9 action structs
- `crates/editor/src/editor.rs` - Implemented fold_at_level_1-9 handler
methods
- `crates/editor/src/element.rs` - Registered new actions
- `assets/keymaps/*.json` - Updated keybindings to use new individual
actions
### Other Approaches considered
- Adding #[serde(default)] to existing FoldAtLevel(u32) - wouldn't make
it discoverable
- Creating a single action with enumerated variants - idk about this
that well.
### Release Notes
Release Notes:
- Added Fold At Level 1-9 actions to the command palette
---------
Co-authored-by: HactarCE <6060305+HactarCE@users.noreply.github.com>
096930817b