RF Interfaces: conform to pydantic models

While implementing validation for Oxygen's handler result dictionaries, it was
found out that RobotInterface.running assumed result dictionaries would have
fields that are not, in fact, mandatory. Thus, add robust attribute handling
to both RF3- and RF4 interfaces.

src/oxygen/robot3_interface.py

@@ -343,7 +343,7 @@ def create_wrapper_keyword(self,
 class RobotRunningInterface(object):
     def build_suite(self, parsed_results):
         robot_root_suite = RobotRunningSuite(parsed_results['name'])
-        for parsed_suite in parsed_results['suites']:
+        for parsed_suite in parsed_results.get('suites', []):
             robot_suite = robot_root_suite.suites.create(parsed_suite['name'])
             for subsuite in parsed_suite.get('suites', []):
                 robot_subsuite = self.build_suite(subsuite)
@@ -355,9 +355,9 @@ def build_suite(self, parsed_results):
     def build_tests(self, oxygen_suite, robot_suite):
         for parsed_test in oxygen_suite.get('tests', []):
             name = parsed_test['name']
-            tags = parsed_test['tags']
+            tags = parsed_test.get('tags', [])
             kw = parsed_test['keywords'][0]
-            msg = '\n'.join(kw['messages'])
+            msg = '\n'.join(kw.get('messages', []))
             test_robot_counterpart = robot_suite.tests.create(name, tags=tags)
             if kw['pass']:
                 args = [msg if msg else 'Test passed :D']

src/oxygen/robot4_interface.py

@@ -343,7 +343,7 @@ def create_wrapper_keyword(self,
 class RobotRunningInterface(object):
     def build_suite(self, parsed_results):
         robot_root_suite = RobotRunningSuite(parsed_results['name'])
-        for parsed_suite in parsed_results['suites']:
+        for parsed_suite in parsed_results.get('suites', []):
             robot_suite = robot_root_suite.suites.create(parsed_suite['name'])
             for subsuite in parsed_suite.get('suites', []):
                 robot_subsuite = self.build_suite(subsuite)
@@ -355,9 +355,9 @@ def build_suite(self, parsed_results):
     def build_tests(self, oxygen_suite, robot_suite):
         for parsed_test in oxygen_suite.get('tests', []):
             name = parsed_test['name']
-            tags = parsed_test['tags']
+            tags = parsed_test.get('tags', [])
             kw = parsed_test['keywords'][0]
-            msg = '\n'.join(kw['messages'])
+            msg = '\n'.join(kw.get('messages', []))
             test_robot_counterpart = robot_suite.tests.create(name, tags=tags)
             if kw['pass']:
                 args = [msg if msg else 'Test passed :D']