Add script execution timestamp to editor status

AsyncTaskResult objects store timestamp as string during
construction. This stamp is displayed in the editor status
window whenever a script is run.

Refs #24479

qt/python/mantidqt/utils/asynchronous.py

@@ -110,6 +110,7 @@ class AsyncTaskResult(object):
 
     def __init__(self, elapsed_time):
         self.elapsed_time = elapsed_time
+        self.timestamp = time.ctime()
 
 
 class AsyncTaskSuccess(AsyncTaskResult):

qt/python/mantidqt/widgets/codeeditor/interpreter.py

@@ -27,7 +27,7 @@ from mantidqt.io import open_a_file_dialog
 
 # Status messages
 IDLE_STATUS_MSG = "Status: Idle."
-LAST_JOB_MSG_TEMPLATE = "Last job completed {} in {:.3f}s"
+LAST_JOB_MSG_TEMPLATE = "Last job completed {} at {} in {:.3f}s"
 RUNNING_STATUS_MSG = "Status: Running"
 
 # Editor
@@ -237,7 +237,7 @@ class PythonFileInterpreterPresenter(QObject):
 
     def _on_exec_success(self, task_result):
         self.view.editor.updateCompletionAPI(self.model.generate_calltips())
-        self._finish(success=True, elapsed_time=task_result.elapsed_time)
+        self._finish(success=True, task_result=task_result)
 
     def _on_exec_error(self, task_error):
         exc_type, exc_value, exc_stack = task_error.exc_type, task_error.exc_value, \
@@ -251,19 +251,19 @@ class PythonFileInterpreterPresenter(QObject):
             lineno = -1
         sys.stderr.write(self._error_formatter.format(exc_type, exc_value, exc_stack) + os.linesep)
         self.view.editor.updateProgressMarker(lineno, True)
-        self._finish(success=False, elapsed_time=task_error.elapsed_time)
+        self._finish(success=False, task_result=task_error)
 
-    def _finish(self, success, elapsed_time):
+    def _finish(self, success, task_result):
         status = 'successfully' if success else 'with errors'
-        self.view.set_status_message(self._create_status_msg(status,
-                                                             elapsed_time))
+        status_message = self._create_status_msg(status, task_result.timestamp,
+                                                 task_result.elapsed_time)
+        self.view.set_status_message(status_message)
         self.view.set_editor_readonly(False)
         self.is_executing = False
 
-    def _create_status_msg(self, status, elapsed_time):
+    def _create_status_msg(self, status, timestamp, elapsed_time):
         return IDLE_STATUS_MSG + ' ' + \
-               LAST_JOB_MSG_TEMPLATE.format(status,
-                                            elapsed_time)
+               LAST_JOB_MSG_TEMPLATE.format(status, timestamp, elapsed_time)
 
     def _on_progress_update(self, lineno):
         """Update progress on the view taking into account if a selection of code is