[keymgr_dpe, testenv.] Verify boot_stage_counter for DPE context

### Description

All the test under `.sw/device/tests/crypto/` verified the state of the original `keymgr` during the `test_setup()` (It was required to be inside the **OwnerRootKey** State). However the `keymgr_dpe` does not support this feature as the **FSM** and the key state (**CreatorRootKey** / **OwnerIntKey** / **OwnerKey**) for each _DPE slot_ are not coupled together anymore.

Implement the same check during secure boot and in several other tests.

In the future there will be a feature to poll the key state for each individual _DPE slot_. As soon as this feature is implemented, integrate it inside the corresponding tests.