chore: code refactor to add assertion

[rscampos]

1. Explain what the PR does

fix: #3475

3645eaa chore: code refactor to add assertion
e1ec4b2 chore: enable unchecked-type-assertion

3645eaa chore: code refactor to add assertion

Refactored code to fix the unchecked type cast issue by
incorporating error handling after the type assertion.

2. Explain how to test it

3. Other comments

[yanivagman]

One nit comment, otherwise LGTM

[yanivagman]

nit:

Suggested change

	if ok {
	if !ok {
	return -1
	}

[rscampos]

Thanks for the review. If we do so we still need do add another return in the final in case the switch is not satisfied (e.g: severityValue is 5).

Another thing, just realized it, but I think this func should follow the same logic as threat.pb.go:

tracee/api/v1beta1/threat.pb.go

Lines 136 to 141 in cd6759e

	func (x *Threat) GetSeverity() Severity {
	if x != nil {
	return x.Severity
	}
	return Severity_INFO
	}

If any error is found, we should return Severity_INFO (0) and not (-1). If so, it should be:

func getSeverity(metadata map[string]interface{}) pb.Severity {
	severityValue, ok := metadata["Severity"].(int)
	if ok {
		switch severityValue {
		case 0:
			return pb.Severity_INFO
		case 1:
			return pb.Severity_LOW
		case 2:
			return pb.Severity_MEDIUM
		case 3:
			return pb.Severity_HIGH
		case 4:
			return pb.Severity_CRITICAL
		}
	}

	return pb.Severity_INFO
}

[yanivagman]

Right. The nit here was just about removing the extra indentation of the switch case

[rscampos]

@yanivagman rework on this function and now is return pb.Severity_INFO as default

[yanivagman]

makes sense