Add tests for the new slot management mechanism

Add unit tests for handle allocation and release.
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 56ce933..21cdfab 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -116,6 +116,7 @@
 add_test_suite(psa_crypto_init)
 add_test_suite(psa_crypto_metadata)
 add_test_suite(psa_crypto_persistent_key)
+add_test_suite(psa_crypto_slot_management)
 add_test_suite(psa_crypto_storage_file)
 add_test_suite(shax)
 add_test_suite(ssl)