Remove exceptions from #4734

#4734 introduced some type checking into a number of filters in order to remove notices that were being raised about "array to string" conversions. However, it did so by raising exceptions, which will be a non-starter for anybody who was previously passing arrays and/or objects to these filters.

Likely the more appropriate method would be to simply return the value presented, and potentially raise an `E_USER_WARNING` indicating the filter's inability to process the value.