Added an event for default rule "Unprivileged Delegation of Page Faults Handling to a Userspace Process"

[GLVSKiriti]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind documentation

/kind tests

/kind feature

Any specific area of the project related to this PR?

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/area commands

/area pkg

/area events

What this PR does / why we need it: Added an event for default rule "Unprivileged Delegation of Page Faults Handling to a Userspace Process" as mentioned here

Which issue(s) this PR fixes:

Fixes #170

Special notes for your reviewer:

[GLVSKiriti]

This event is also tested against a running a falco instance and produces the critical priority log as expected on left terminal

[GLVSKiriti]

@FedeDP similarly this triggers irrespective of userfaultfd syscall is successful or not just an attempt is enough to trigger the rule so return nil; https://github.com/falcosecurity/event-generator/blob/d8b3ae6f330d1ece430ec703cc384cd5010cbdd3/events/syscall/unprivileged_delegation_of_page_faults_handling_to_a_userspace_process.go#L31-L37

[poiana]

LGTM label has been added.

Git tree hash: ba7791d58984e180ddf7bc4b6a26b92443fbf5a4

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: GLVSKiriti, leogr

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