[FIX] core: log error on addSubTest

Since #34996, in some case, the error detail was not logged keeping
only the final summary "x errors, x failures" when running TestSuite.

Making fail test test_cache_invalidation for instance won't show
a detailed message when breaking test_01_project_tour will.
This issue occurs when using subtest, like with assertQueryCount,
@users decorator, test_all_l10n, and test_youtube_urls.

Since Testresult addSubTest append directly to error and failures
instead of calling addError and addFailure, we need to ovewrite
addSubtest too.

closes odoo/odoo#35270

Signed-off-by: Denis Ledoux <beledouxdenis@users.noreply.github.com>

odoo/modules/module.py

@@ -511,6 +511,17 @@ class OdooTestResult(unittest.result.TestResult):
         super().addFailure(test, err)
         self.logError("FAIL", test, err)
 
+    def addSubTest(self, test, subtest, err):
+        # since addSubTest is not making a call to addFailure or addError we need to manage it too
+        # https://github.com/python/cpython/blob/3.7/Lib/unittest/result.py#L136
+        if err is not None:
+            if issubclass(err[0], test.failureException):
+                flavour = "FAIL"
+            else:
+                flavour = "ERROR"
+            self.logError(flavour, subtest, err)
+        super().addSubTest(test, subtest, err)
+
     def addSkip(self, test, reason):
         super().addSkip(test, reason)
         self.log(logging.INFO, 'skipped %s', self.getDescription(test), test=test)