Fix to #11048

Motivation

Adding correct validation for ARN inputs to ssm get-parameter and ssm get-parameters

Changes

Adds an internal validation method to localstack.services.ssm.provider.SSMProvider (._normalize_name_or_arn) which validates either ARNs or parameter names, and throws errors consistent with the AWS implementation (to the best of my knowledge).

Testing

• Added unit test TestSSM.test_get_parameter_by_arn

TODO

• Add parity test to verify comparability responses (these should pass already, but have not implemented)
• Partity test: incorrect ARN format, with regex pattern ^arn:aws:.+:.+:.+:.+$
  • Test designed to check parity with call aws ssm get-parameter --name arn:
• Parity test: invalid region (either not matching a valid AWS region, or not the same region as the call context)
  • Test designed to check parity with call aws ssm get-parameter --name arn:aws:service:incorrect-region:0000000000:parameter/myparam
  • Note that the official implementation does not check that the service name is correct (i.e. there is no stipulation that service in the above is ssm; the following passes validation: aws ssm get-parameter --name arn:aws:service:us-east-1:0000000000:parameter/myparam)