- Introduced a button to dynamically set the expression in the substitution line.
- The feature is available for converters of type "Odoo template", "Odoo template + Evaluation", and "Field".
- Added functionality to visualize how to define each converter, displaying a placeholder (example) for each converter type.
- The code has been designed to ease the integration of additional converters in the future.
- Refactored the code to improve performance and stability.

- Add missing python-magic requirement for package

& latest xcg/templates/odoo_module.

Add rednerd template management API to let the user save templates
for later use with the rendering api:

- POST: /api/v1/template/{account}
- PUT: /api/v1/template/{account}/{name}
- DELELTE: /api/v1/template/{account}/{name}

Render a custom template:

- POST: /api/v1/render