Add type and direction infos in Annotation class

[Flanker32]

background issue https://github.com/Microsoft/azure-maven-plugins/issues/456

There used to be strong dependency between function maven plugin and function java library, and now we change to use java reflect to get attributes from annotation to reduce the dependency (PR https://github.com/Microsoft/azure-maven-plugins/pull/508). However, we still need to store annotation type and direction infos in our enum class for we can't get them from annotations. So could you please add the infos in annotations of java library, like add an annotation? If so, all needed informations could comming from java library directly. Besides, could you please update the function.json scheme? Schema could be much helpful in local validation and users could verify and update their code according to schema as well

[pragnagopa]

cc: @soninaren Will look into this.

[jdneo]

@pragnagopa We are considering to add some verification logic in the Maven tooling when generating the functions.json. So what we are missing here is the detailed information about each property of an annotation. For example, whether this property is required or not.