**What**
Add pub key + sales channel middlewares to the store carts API
- Assign sales channel associated with pub key, if sales channel is not passed in request
- Throw if pub key has multiple associated sales channels
- Throw if sales channel ID in payload is not associated with publishable API key in header
**What**
- automatically build and consume connection and container loader if not exported by the module
- therefore load the services and repositories automatically, including baseRepository
- automatically build run and revert migrations if not provided
- cleaup modules to remove extra unnecessary bits and pieces
- remove the `initializeFactory` in favor of using `medusaApp`
Should drastically improve the module building DX by removing a lot of boilerplate to handle by the user, that plus the base entity should simplify quite a lot the flow cc @shahednasser
**Note**
I had to choose a way to identify connection and container loader from the exported loader from the module. I decided to go with named function `connectionLoader` and `containerLoader`, also, now the factories will return named function so if the user use the factories we are providing to build those loaders, the function will also be named and identified
**What**
Provide a new mikro orm base entity in order to abstract away the on init and on create which include the id auto generation if not provided. The main goal is to reduce complexity in entity definition
Noticed that `RequestQueryFields` is defined in both the `medusa` and `types` package. Within the `medusa` package sometimes it uses the local type definition or the definition in `types`.
This PR removes the type definition of `RequestQueryFields` in `medusa` and uses that in `types` instead.
