Support for trace files with Verbose format in Hatchet/Thicket

[alizalisan]

@tpatki @spencer-gre

• Currently, we only support trace files with compact format in Hatchet/Thicket.
• The reason for not supporting verbose format is that it is not easy to link the ending ("E") event of a function with its begin ("B") event. Especially in the case of multiple calls to the same function.