feat: new write_and_close event

[qjerome]

This PR contains the changes needed to have a new event write_and_close

This event would be generated when a file gets closed after being written.
Motivation:

• write event is generated only when the file is first written
• write event is generated only once per task so if the file gets written once again (by the same task) I'll not be shown again
• such an event is a great trigger for file scanning as we are sure the file got closed (which is not the case of write event)

This PR also contains some little refactoring:

• renamed userland structures encoding file events
• bpf file tracking