Fix error invalid URL escape "% ^"

[ParthaI]

Describe the bug
The UnmarshalYAML() leveraged yaml.Unmarshal() from the Go package github.com/ghodss/yaml and url.QueryUnescape from net/url to decode and parse YAML into JSON.
The function QueryUnescape returns an error if any % is not followed by two hexadecimal digits.
Additionally, the function UnmarshalYAML was also throwing an error for the code block in the template.

Steampipe version (steampipe -v)
Example: Steampipe v0.21.3

Plugin version (steampipe plugin list)
Example: Steampipe plugin AWS 0.129.0

To reproduce
Try to parse the following template content:

CopyZipsFunction:
    Type: AWS::Lambda::Function
    Properties:
      Description: Copies objects from a source S3 bucket to a destination
      Handler: index.handler
      Runtime: python3.8
      Role: !GetAtt "CopyZipsRole.Arn"
      Timeout: 240
      Code:
        ZipFile: |
          import json
          import logging
          import threading
          import boto3
          import cfnresponse
          def copy_objects(source_bucket, dest_bucket, prefix, objects):
              s3 = boto3.client('s3')
              for o in objects:
                  key = prefix + o
                  copy_source = {
                      'Bucket': source_bucket,
                      'Key': key
                  }
                  print('copy_source: %s' % copy_source)
                  print('dest_bucket = %s'%dest_bucket)
                  print('key = %s' %key)
                  s3.copy_object(CopySource=copy_source, Bucket=dest_bucket,
                        Key=key)
          def delete_objects(bucket, prefix, objects):
              s3 = boto3.client('s3')
              objects = {'Objects': [{'Key': prefix + o} for o in objects]}
              s3.delete_objects(Bucket=bucket, Delete=objects)
          def timeout(event, context):
              logging.error('Execution is about to time out, sending failure response to CloudFormation')
              cfnresponse.send(event, context, cfnresponse.FAILED, {}, None)
          def handler(event, context):
              # make sure we send a failure to CloudFormation if the function
              # is going to timeout
              timer = threading.Timer((context.get_remaining_time_in_millis()
                        / 1000.00) - 0.5, timeout, args=[event, context])
              timer.start()
              print('Received event: %s' % json.dumps(event))
              status = cfnresponse.SUCCESS
              try:
                  source_bucket = event['ResourceProperties']['SourceBucket']
                  dest_bucket = event['ResourceProperties']['DestBucket']
                  prefix = event['ResourceProperties']['Prefix']
                  objects = event['ResourceProperties']['Objects']
                  if event['RequestType'] == 'Delete':
                      delete_objects(dest_bucket, prefix, objects)
                  else:
                      copy_objects(source_bucket, dest_bucket, prefix, objects)
              except Exception as e:
                  logging.error('Exception: %s' % e, exc_info=True)
                  status = cfnresponse.FAILED
              finally:
                  timer.cancel()
                  cfnresponse.send(event, context, status, {}, None)

Expected behavior
We should be able to parse the YAML content to JSON without any error.

Additional context
N/A