AWS::WAF::WebACL tagging

[ionutz89]

##Scope of request

####Currently, we can add tags to AWS WAF only by using CLI:

aws waf tag-resource --resource-arn arn:aws:waf::XXXXXXXXXXXXX:webacl/12340-12234-23452-233455 --tags "Key=tag1,Value=values2

###It will be great if this option can be added to Cloudformation as well.

##Helpful Links to speed up research and evaluation

####https://docs.aws.amazon.com/cli/latest/reference/waf/tag-resource.html

##Category Security

##I think we should also add tags support to "Type": "AWS::WAFRegional::WebACL"

[piotrekwitkowski]

Customers can migrate their WebACLs to WAFv2. AWS::WAFv2::WebACL supports setting tags. https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-wafv2-webacl.html