Add SNS Service "Publish" operation to the aws_para_whitelist

[Tankanow]

Currently the SNS publish operation shows up with a minimum set of metadata:

"aws": {
    "operation": "Publish",
    "region": "us-east-1",
    "request_id": "a939cee1-7c48-5675-b385-9ae2206dc121"
}

This should include at least the known internal AWS resources like TopicArn or TargetArn and maybe even the PhoneNumber.

[Tankanow]

I will happily work on this if it's not on the roadmap.

[haotianw465]

Hi, PhoneNumber is relatively sensitive and recording it by default is probably not a good idea. TopicArn on the other hand would be a vey useful information. Feel free to add it to the whitelist by submitting a PR and some unit test.