Add simple escape method for special characters to template query

The default mustache engine was using HTML escaping which breaks queries
if used with JSON etc. This commit adds escaping for:

```
\b  Backspace (ascii code 08)
\f  Form feed (ascii code 0C)
\n  New line
\r  Carriage return
\t  Tab
\v  Vertical tab
\"  Double quote
\\  Backslash
```

Closes #5473