Add V2 sales channel management to admin
`@medusajs/medusa`
- Add `POST /admin/sales-channels/:id/products/batch/remove`
- Refactor cross-module filter middleware to comply with the latest convention
`@medusajs/admin-next`
- Add all sales channel routes
- Moves the following sales channel UI to shared components in `modules/sales-channel`:
- sales-channel-list
- sales-channel-edit
- sales-channel-details
- sales-channel-general-section
- sales-channel-create
The sales-channel-product-section is not shared because the API in V2 will change.
The sales-channel-add-products component is not shared because the API in V2 will change.
`@medusajs/core-flows`
- Add `detachProductsFromSalesChannelsStep`
- Add `removeProductsFromSalesChannelsWorkflow`