Delete control characters from all recording event properties

Found another case where the html5 client was passing through control
characters, in the original presentation name field.

Rather than play whack-a-mole with different fields which may eventually
get poorly sanitized user data, apply the control character filtering
to all properties.

Adjust the character range to do the following:
* Allow horizontal tab (0x09), it's not problematic.
* Disallow control characters in the range 0x1A-0x1F. Probably missed by accident.