fix: (OData v4) Use correct ETag / If-Match header for entity bound actions

[newtork]

Context

Addresses #870

We've been adding the incorrect HTTP request header when supplying the entity version ETag.

Feature scope:

• Fix for bound actions with single value return type
• Fix for bound actions with multi value return type
• Ignore bound functions, since according to OData standard they must be free of side-effects

ETags in OData v4

• Clients can then use them in conditional requests (e.g. If-Match / If-None-Match headers) when doing PATCH, DELETE, or other state-modifying operations.

Affected API (Example)

No change for user code.

var service = new DefaultSdkGroceryStoreService();

var customer = Customer.builder().id(1337).build();
customer.setVersionIdentifier("123"); // implicit

var  historyItems = service.forEntity(customer)
        .applyAction(
            Customer
                .filterPurchaseHistory(
                    List.of(Receipt.builder().customerId(1337).id(4242).build()),
                    List.of("milk", "eggs"),
                    List.of(ProductCategory.DAIRY, ProductCategory.MEAT),
                    dateRange))
        .execute(destination);

Definition of Done

• Functionality scope stated & covered
• Tests cover the scope above
• Error handling created / updated & covered by the tests above
• Documentation updated
• Release notes updated

[Jonas-Isr]

LGTM