**What**
- Changes all forms to only submit on Cmd/Ctrl + Enter instead of just Enter.
- Cleans up the position of submit/cancel buttons in many FocusModals that still had them in the header.
- Fixes responsiveness of multiple forms
- Removes the SplitView component, and replaces its usages with StackedDrawer/Modal to align the UX across the project.
Resolves CC-103, CC-535
**What**
- Renames /admin-next -> /admin
- Renames @medusajs/admin-sdk -> @medusajs/admin-bundler
- Creates a new package called @medusajs/admin-sdk that will hold all tooling relevant to creating admin extensions. This is currently `defineRouteConfig` and `defineWidgetConfig`, but will eventually also export methods for adding custom fields, register translation, etc.
- cc: @shahednasser we should update the examples in the docs so these functions are imported from `@medusajs/admin-sdk`. People will also need to install the package in their project, as it's no longer a transient dependency.
- cc: @olivermrbl we might want to publish a changelog when this is merged, as it is a breaking change, and will require people to import the `defineXConfig` from the new package instead of `@medusajs/admin-shared`.
- Updates CODEOWNERS so /admin packages does not require a review from the UI team.
