Create a new ##id## tag to use in Database activity templates

As a teacher
I want to identify an element by a unique id on a Database template
so I can apply styling and behavior to the element

For some of the new templates defined on the Database project prototype we need some elements to be collapsable. To implement this accordion behavior in an easy way, we need to identify the elements by the id.

A new ##id## tag will be added to templates so the users and the new presets could use to implement the behavior they need.

Prototype: https://www.figma.com/proto/vmspDJsBAYrPfECMrgpGEd/4.1-Database?page-id=0%3A1&node-id=288%3A105628&viewport=90%2C15691%2C0.25&scaling=scale-down&starting-point-node-id=288%3A105628&show-proto-sidebar=1

This issue is part of the Moodle 4.1 database module project. All the related code to this issue that does not follow the current coding style or present maintenance problems will be refactored. In this case, the refactored areas are focused in 3 main areas:

• Create a generic mod_data\manager class for the mod_data (similar to the one used in mod_h5pactivity)
• Refactor the template editor to use output classes and mustache files (the functionality will remain the same)
• Refactor the print entry parser into its own class mod_data\template and use it instead of the current global function