Allow execution of Puppet functions from Hiera

[tuxmea]

It should be possible to call puppet functions directly from Hiera. e.g.

stdlib::manage::create_resources:
  file:
    '/etc/app/db.cfg':
      ensure: 'file'
      content: "%{epp('profile/app/db.cfg.epp')}"

Hiera should then return the epp parsed content.

How are we able to solve this? Which syntax would be possible or recommended?