[Metricbeat] Add cloud.account.id into events from aws module

[kaiyan-sheng]

This PR is to add the ability to collect cloud.account.id and cloud.account.name into aws module. More user-friendly, account alias(For example: elastic-kaiyan-aws) is preferred than the account id(For example: 123456789).

cloud.account.name can be empty because for aws account, alias is not required.

closes #13551

How to test this:

With this change, if you enable any metricset under aws module and check in Kibana, you should see cloud.account.id in the event. If the account alias is set, then cloud.account.name should exist as well in the new event.

[sayden]

LGTM. One question. Does it removes completely the ID from the event? I don't see a real need for it but, who knows, maybe it's mandatory for someone.

Ah! And I have to ask for the mandatory new binary size after adding more packages 😬

[kaiyan-sheng]

@sayden Thanks for the review 😬 No, it does not remove ID from the event. It only adds a new field for the cloud account. Regarding to the binary size, I'm actually not sure why this time, it added all files under aws/aws-sdk-go-v2/service/iam hmm

[exekias]

sorry for the late comment, just a double check: Do we need to document any added permission for this to work?

[kaiyan-sheng]

sorry for the late comment, just a double check: Do we need to document any added permission for this to work?

@exekias You are absolutely right! Yes, two more permissions are needed. I will push a separate PR to add it. Thanks!