Security group rule description not validated

[j-boivie]

cfn-lint version: cfn-lint 0.29.5

I came across a small problem similar to the issue described in #173. Security group rule descriptions have some constraints on characters/length allowed (docs) and it seems like these are not being checked by cfn-lint.

The following snippet will be accepted by cfn-lint but cause an issue during deployment:

LbSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Load Balancer SG
      VpcId: !Ref VPC
      SecurityGroupIngress:
        - Description: -> doesn't work
          CidrIp: 0.0.0.0/0
          FromPort: 80
          ToPort: 80

Which would result in this:
Invalid rule description. Valid descriptions are strings less than 256 characters from the following set: a-zA-Z0-9. _-:/()#,@[]+=&;{}!$*

Unsure if this also applies when using Ingress rule resource AWS::EC2::SecurityGroupIngress as there is no similar constraint in the docs.

Thanks!

[PatMyron]

As described here, this would need something like:

https://github.com/aws-cloudformation/cfn-python-lint/blob/a46773c752247c51effef415bd3462eaec10ab0b/src/cfnlint/data/ExtendedSpecs/all/03_value_types.json#L33-L36

https://github.com/aws-cloudformation/cfn-python-lint/blob/a46773c752247c51effef415bd3462eaec10ab0b/src/cfnlint/data/ExtendedSpecs/all/04_property_values.json#L330-L336

and the rest of the necessary changes should be auto-generatable by running:

cfn-python-lint $ pip3 install -e . --user
cfn-python-lint $ cfn-lint --update-specs

---

There should be no functional difference, but src/cfnlint/data/ExtendedSpecs/all/03_value_types and src/cfnlint/data/ExtendedSpecs/all/04_property_values are more organized than src/cfnlint/data/ExtendedSpecs/all/03_value_types.json and src/cfnlint/data/ExtendedSpecs/all/04_property_values.json, so they should be preferred locations for new constraints