Fixed editor log path and improved editor log not found error string (#5357)

* Fixed editor log path and improved editor log not found error string

* Renamed any lowercase editor.log to Editor.log

* Fix unit test failures

Signed-off-by: AMZN-AlexOteiza <aljanru@amazon.co.uk>

Co-authored-by: aljanru <aljanru@uc5564ff5a5ee55.ant.amazon.com>

Tools/LyTestTools/tests/unit/test_manager_platforms_windows.py

@@ -80,7 +80,7 @@ class TestWindowsResourceLocator(object):
             mock_build_directory, mock_project)
         expected = os.path.join(
             windows_resource_locator.project_log(),
-            'editor.log')
+            'Editor.log')
 
         assert windows_resource_locator.editor_log() == expected