docs: updates to use DML and other changes (#7834)

- Change existing data model guides and add new ones for DML
- Change module's docs around service factory + remove guides that are now necessary
- Hide/remove all mentions of module relationships, or label them as coming soon.
- Change all data model creation snippets to use DML
- use `property` instead of `field` when referring to a data model's properties.
- Fix all snippets in commerce module guides to use new method suffix (no more main model methods)
- Rework recipes, removing/hiding a lot of sections as a lot of recipes are incomplete with the current state of DML.


### Other changes

- Highlight fixes in some guides
- Remove feature flags guide
- Fix code block styles when there are no line numbers.

### Upcoming changes in other PRs

- Re-generate commerce module references (for the updates in the method names)
- Ensure that the data model references are generated correctly for models using DML.
- (probably at a very later point) revisit recipes

www/apps/book/app/basics/workflows/page.mdx

@@ -228,11 +228,11 @@ Each step in the workflow receives as a second parameter a `context` object. The
 For example:
 
 export const highlights = [
-  ["14", "resolve", "Resolve the `IProductModuleService`."],
-  ["14", "ModuleRegistrationName.PRODUCT", "The resource registration name imported from `@medusajs/modules-sdk`."]
+  ["15", "resolve", "Resolve the Product Module's main service."],
+  ["15", "ModuleRegistrationName.PRODUCT", "The resource registration name imported from `@medusajs/modules-sdk`."]
 ]
 
-```ts title="src/workflows/product-count.ts" highlights={highlights}
+```ts title="src/workflows/product-count.ts" highlights={highlights} collapsibleLines="1-12" expandButtonLabel="Show Imports"
 import {
   createStep,
   StepResponse,
@@ -265,4 +265,6 @@ const myWorkflow = createWorkflow<unknown, WorkflowOutput>(
 )
 
 export default myWorkflow
-```
+```
+
+In the step, you resolve the Product Module's main service and use it to retrieve the product count.