Incorporate `x-ms-identifiers` swagger annotation into generated types

**x-ms-identifiers**
Indicates the identifying property for objects in arrays
* Options
- Can provide multiple identifiers in the array to form composite identifier
- Can use JSON pointer to point to identifier that is inner property, e.g., /properties/subnet/id
* Example

```json
"myArrayProperty": {
"type":"array",
"items": {
"$ref":"#/definitions/Example"
},
"x-ms-identifiers": ["itemName"]
}
```

The issue names no files, tests, or generator entry point. Start by locating the swagger-to-generated-types pipeline and its handling of array annotations, then use the supplied x-ms-identifiers example, including composite identifiers and JSON Pointer identifiers, to define verification.

Written by the indexing model from the issue text.