[Draft] - potential workaround for #520

This is some pretty sketchy code, but it seems to work. Just throwing out some ideas for how we might want to fix this.

Before writing to the database, this code replaces all the non-ascii characters with their \u encoding by calling  `create_escapes` method from property tree's json writer. Going forward, we would probably want to replace that with something else.

Is `addNewResults` where we want to make this change?
Depends, I'm cool with a const_cast such that you can, OR we remove the const qualifier.

Though now that I'm thinking a bit more if folks do weird things with the QueryData afterward (after addNewResults) the results will be undefined. So yeah, your implementation is best!