Add test driver support for opaque key import

-Add test driver support to import/export while wrapping keys
 meant to be stored in the PSA core as opaque( emulating an
 SE without storage ).
-Export validate_unstructured_key_bit_size as
 psa_validate_unstructured_key_bit_size, thereby changing its scope.
-Improve the import/export test cases in test_suite_psa_crypto to also
 cover opaque keys, thereby avoiding duplication.

Signed-off-by: Archana <archana.madhavan@silabs.com>
diff --git a/library/psa_crypto_ecp.h b/library/psa_crypto_ecp.h
index 0c2b928..dc9e887 100644
--- a/library/psa_crypto_ecp.h
+++ b/library/psa_crypto_ecp.h
@@ -224,13 +224,13 @@
 
 #if defined(PSA_CRYPTO_DRIVER_TEST)
 
-psa_status_t mbedtls_transparent_test_driver_ecp_import_key(
+psa_status_t mbedtls_test_driver_ecp_import_key(
     const psa_key_attributes_t *attributes,
     const uint8_t *data, size_t data_length,
     uint8_t *key_buffer, size_t key_buffer_size,
     size_t *key_buffer_length, size_t *bits );
 
-psa_status_t mbedtls_transparent_test_driver_ecp_export_public_key(
+psa_status_t mbedtls_test_driver_ecp_export_public_key(
     const psa_key_attributes_t *attributes,
     const uint8_t *key_buffer, size_t key_buffer_size,
     uint8_t *data, size_t data_size, size_t *data_length );