Pass MockedRequest with additional getters to mirage handler

[mrloop]

In my case I want to use the getter body with parsed form-data

• https://github.com/mswjs/msw/blob/main/src/utils/request/MockedRequest.ts
• https://github.com/mswjs/msw/blob/156e80bd39dde08fcf0cb9e7c93221798fe8e3c9/src/utils/request/parseBody.ts#L20