fix(interpreter): compare values from 'verifyEval'

This is an attempt to fix an issue described in (se-builder/#163)[https://github.com/sebuilder/se-builder/issues/163] 
which allows comparison of evaluated values.

Example:
{
  "type": "verifyEval",
  "script": "return true;",
  "value": "true"
}

Before: Error: "true" does not match "true"
After: true