Refactor and simplify legacy syscall_event_drops

[incertum]

Refactor and simplify legacy syscall_event_drops.

Previous discussion: #2910

Needs to address CVE-2019-8339 even better.
@leogr to provide more details.

[incertum]

/milestone 0.38.0

/assign @leogr

[incertum]

Initial ideas:

• Add an explicit enabled key to allow for easier opt out
• By default enabled for all logging levels not just priority level debug
• Only report global drop stats and instead point to metrics for detailed and continuous monitoring
• Discuss alert volume implications -> opportunity to re-design and adopt a new approach

[poiana]

Issues go stale after 90d of inactivity.

Mark the issue as fresh with /remove-lifecycle stale.

Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

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/lifecycle stale

[Andreagit97]

/remove-lifecycle stale

[LucaGuerra]

Is this addressed by the latest changes in Falco or shall we move it to the next milestone?

/milestone 0.39.0

[incertum]

We haven't gotten to it, so 0.39.0 is perfect. Thanks!

[poiana]

Issues go stale after 90d of inactivity.

Mark the issue as fresh with /remove-lifecycle stale.

Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Provide feedback via https://github.com/falcosecurity/community.

/lifecycle stale

[incertum]

/remove-lifecycle stale

next milestone

[poiana]

Issues go stale after 90d of inactivity.

Mark the issue as fresh with /remove-lifecycle stale.

Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Provide feedback via https://github.com/falcosecurity/community.

/lifecycle stale

[Andreagit97]

/remove-lifecycle stale