Make OriginReadTimeout configurable for custom origins

[Harriebo]

We use the custom origins to map the old api while moving to NextJs which contain some old endoints which need a higher timeout, at this moment we cant use the serverless config to set this since its hardcoded to 30.

https://github.com/serverless-components/aws-cloudfront/blob/6f15e0733e27c80ad16723d7c8452657f75d0fd9/lib/getOriginConfig.js#L36

for example:

    cloudfront:
      origins:
        - url: https://url/
          originReadTimeout: 60
          pathPatterns:
            /old-api/*:
              allowedHttpMethods: [GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE]

[Harriebo]

At this point this feature is blocking for us, if this is not resolved we will have to move away from the serverless component for our nextJs migration. Since it resets all manual changes every deploy, it will break our rolling deploy system and thus become unusable.