More precise name for test data generation

We have Python code both for test code generation
(tests/scripts/generate_test_code.py) and now for test data generation.
Avoid the ambiguous expression "test generation".

This commit renames the Python module and adjusts all references to it. A
subsequent commit will adjust the documentation.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/generate_psa_tests.py b/tests/scripts/generate_psa_tests.py
index 867a6b4..e7d4048 100755
--- a/tests/scripts/generate_psa_tests.py
+++ b/tests/scripts/generate_psa_tests.py
@@ -30,7 +30,7 @@
 from mbedtls_dev import macro_collector
 from mbedtls_dev import psa_storage
 from mbedtls_dev import test_case
-from mbedtls_dev import test_generation
+from mbedtls_dev import test_data_generation
 
 
 def psa_want_symbol(name: str) -> str:
@@ -894,7 +894,7 @@
         yield from super().generate_all_keys()
         yield from self.all_keys_for_implicit_usage()
 
-class PSATestGenerator(test_generation.TestGenerator):
+class PSATestGenerator(test_data_generation.TestGenerator):
     """Test generator subclass including PSA targets and info."""
     # Note that targets whose names contain 'test_format' have their content
     # validated by `abi_check.py`.
@@ -919,4 +919,4 @@
         super().generate_target(name, self.info)
 
 if __name__ == '__main__':
-    test_generation.main(sys.argv[1:], __doc__, PSATestGenerator)
+    test_data_generation.main(sys.argv[1:], __doc__, PSATestGenerator)