Add parameters to identify the campaigns that directs traffic.

This feature can be used in a few ways:

OcambaHoood.setUtm("key", "value"); 
//-> we will create “key” key with value “value“ in sdk storage
//-> we will return value of key “key” from sdk storage
//-> key “key” replace will be removed from sdk storage

NOTE: change “key” and “value” to something else. Use this before or just after init function.