Additional Preprocessing Option for human readable values (e.g. disk sizes)

values are received by snmp in human-readable format like "1.23 TB".

in item preprocessing, there are is no option for value conversion to Bytes yet, so that setting "unit" to "B" could show an accurate value.

so nice to have is either a "conditional custom multiplier", like <if regex "TB" then multiply by "1024*1024*1024">
or simply the best possible value conversion of type "filesize"