Support longer than 20 char limit for event serialisation

[#1]

Event serialisation is often the answer to a business requirement however I find more often than not the 20 character limit prevents me from usinging this feature. My most common requirement is to fire an event once per visit per some kind of unique content id. More often than not combining a visit id and content id results in a serial longer than 20 characters

[#2]

This appears to be a duplicate of Increase Character Limit of Serialized Event ID