"quote" Mustache helper only escapes first quote in JS

The JS variant of the "quote" Mustache helper only escapes the first double quote in the string. Responsible for that is this call: https://github.com/moodle/moodle/blob/0dca957716952323bd56089929ac6412136a29f1/lib/amd/src/templates.js#L487

Steps to reproduce the problem:

1. Login as Manager.
2. Add upcoming_events block to your dashboard.
3. Create assignment in one of your courses with:
   • Due date: tomorrow
   • Name: Double "quote" test
4. Go to the dashboard.
   => You get a Syntax error "Unexpected token t in JSON at position 27".