Make escaping for json simpler and more consistent in Mako templates
- add escape_json_dumps to escape and json.dumps
- add escape_js_str to escape javascript string
- refactor Studio to use escape_json_dumps in Mako templates
TNL-2646: Escape json.dumps
- Resolve SEC-27 by escaping course name in advanced settings
- Add escape_json_dumps to simplify escaping json in Mako templates
SEC-27: XSS/JS Error in Advanced Settings with invalid course name