Add priorities for server set errors

[amarziali]

What Does This Do

Similarly to resource names, it adds priority based error flag settings.

The http servers will set error using a lower priority than the user one. The errors set elsewhere will stay untouched (but it should be changed in the future as well).

It solves a particular two use cases:

• The error set by the user should have higher prio than the one set according to a http response status code
• The application server throws an error but, despite logged, the error flag should be set according to the http status code

Motivation

Additional Notes

[pr-commenter]

Benchmarks

Parameters

	Baseline	Candidate
commit	1.16.0-SNAPSHOT~8ac87914bf	1.16.0-SNAPSHOT~74661c498f
config	baseline	candidate

See matching parameters

	Baseline	Candidate
module	Agent	Agent
parent	None	None

Summary

Found 0 performance improvements and 2 performance regressions! Performance is the same for 20 cases.

scenario	Δ mean execution_time
scenario:Startup-base-AppSec	worse [+4.171ms; +4.996ms] or [+8.400%; +10.062%]
scenario:Startup-iast-AppSec	worse [+3.969ms; +4.905ms] or [+8.195%; +10.127%]

[ygree]

I can't see any usages of this method

[amarziali]

it's used by Subclasses (e.g. datadog.trace.instrumentation.tomcat.TomcatDecorator#onResponse calls onError).
Being overridded now http server based decorators are inheriting this behavior

[ygree]

LGTM except for onError method that I can't find any usages for.