[Feature] fall-back Fragment file

[ThrashJazzAssassin]

I have a fragment that gets its filename from a variable @{fx/@{parent.variables.n}/name}.json, it works great, but if the file does not exist, the fragment remains blank and a 'Fragment file not found' error appears in the console. Please implement a field that can direct the fragment to a fall-back fragment file when this happens.

Thank you.

[jean-emmanuel]

Done