Add ECS fields to process & FS resources

[uri-weisman]

The work has been done as part of the ECS mapping epic:

• https://github.com/elastic/security-team/issues/3788
• https://github.com/elastic/security-team/issues/3787

[mergify]

This pull request does not have a backport label. Could you fix it @uri-weisman? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[jeniawhite]

The value of HZ varies across kernel versions and hardware platforms.
There is an assumption here for certain conditions that might not be respected between different deployments and versions.
I think that we can use https://man7.org/linux/man-pages/man3/sysconf.3.html and pull the value of _SC_CLK_TCK in order to reduce this assumption.

[uri-weisman]

Thank you for raising this up @jeniawhite .
It is a borrowed implementation from go-sysinfo, we decided to deliver it with this known limitation while opening 2 new tickets to the go-sysinfo repo.

• Linux kernel ticks assumption is error prone go-sysinfo#122
• Make the "host FS" location configurable go-sysinfo#12

Once those tasks will be delivered, possibly by us, we'll change our implementation to use the go-sysinfo pkg.

[DaveSys911]

LGTM

[DaveSys911]

Could you please set go version using the env var like the unit tests job?

[uri-weisman]

Fixed

[oren-zohar]

shouldn't this sit in the kube_fetcher?

[uri-weisman]

Seems fine to me to reside next to the rest of the Resource interface

type Resource interface {
	GetMetadata() ResourceMetadata
	GetData() any
	GetElasticCommonData() any
}

If you feel this is not the place we can move them all.