add "Condition" field to CFN/SAM schemas

[hauntingEcho]

the CFN/SAM schemas currently support the Conditions top-level object but not the Condition resource property (the sibling of Type and Properties on any resource).

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/conditions-section-structure.html

[xrn]

Each resource has property AWSCloudFormationCondition fell free to use it

[hauntingEcho]

I'm not seeing those in any of the files in the schema folder.

I'm honestly just using the JSON schema files for syntax highlighting in serverless templates - schemastore links those back to here, and is the default JSON/YML schema registry for Jetbrains' IDEs. I'm not sure that a differently-named property would work. From a quick sampling, it does look like each resource's AWSCloudFormationCondition gets marshalled into condition, though.