Cfn-lint

Features
- Update the custom objects for the template to directly allow the calling of getting items and checking items that is condition safe
- Update CloudFormation Specs to 2018-09-21 released specs
Fixes
- Fix rule [E2540](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2540) to not fail when the stage names aren't strings
- Fix rule [E3002](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3002) to not fail when processing Ref AWS::NoValue
- Core functionality updated to fail when extending rules directory doesn't exist
- Fix rule [E3002](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3002) metadata isn't supported as a resource property
- Fix rule [E2509](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2509) to not error when using a function for description

Fixes
- Fix rule [W2501](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W2501) to support dashes in KMS Key name
- Fix rule [E2543](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2543) to not fail when the type of a step isn't known
- Fix rule [E2507](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2507) to have an exception for ECR Policies. Resource isn't required.
- Several Python cleanup items around initializing lists, how version is loaded, and dropping 'discover' in testing

Fixes
- Fix core decoding so the true error of a template parsing issue is visible to the user

Features
- New Rule [W1019](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W1019) to make sure any Sub variables are used in the string
- New Rule [E2532](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2532) to start basic validation of state machine syntax
- New Rule [W1020](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W1020) to see if Sub is needed and variables are being used
- New Rule [E1028](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1028) validate that first element in a Fn::If array is a string
- New Rule [W3002](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W3002) to warn when templated templates are used
- Update Rule [E2507](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E2507) to check resource base policies
- Add Rule [W2511](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#W2511) to warn when using an older version of IAM Policy Version
Fixes
- Update Rule [E3002](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3002) to allow for templated code
- Update Rule [E1024](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1024) to allow Cidr function to use GetAtt
- Fix core functionality to not error if the template is an array or string instead of an object

Fixes
- Fixes an issue where Template.get_values would return `Ref: AWS::NoValue`. This will no longer be returned as it is considered to be a Null value.

Features
- Update formatters to be similar from JSON and text outputs and modularize for easier growth later
- Don't raise an error with [E3020](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E3020) when doing ACM DNS validation registration
- Add rule [E7003](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E7003) to validate that mapping keys are strings.
- Add rule [E1027](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1027) to validate that dynamic reference secure strings are to supported properties
- Add rule [E1004](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E1004) to validate that the Template Description is only a string
- Add rule [E6005](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E6005) to validate that an Output Description is only a string
- Add rule [E6012](https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/rules.md#E6012) to validate that an Output Description is less than the maximum length
Fixes
- Fix core libraries to handle conditions around resource properties so that the resource and property checks still run
- Fix core libraries to handle the special property type `Tag` so that its checked when a rule is doing a Property Check