Support for HTTP PATCH method in Camel-HTTP

Issue

• We need clients to be able to send HTTP PATCH method to our route. A simplified route is attached as an example. Sending an HTTP PATCH will result in an exception:

13:08:31,974 | INFO  | tp1638881215-192 | HandoffOdata                     | 198 - org.apache.camel.camel-core - 2.15.1.redhat-621084 | Handing off to http://abc.def.com/test-service/Contents('test-some_id')?
13:08:31,976 | INFO  | tp1638881215-192 | OdataError                       | 198 - org.apache.camel.camel-core - 2.15.1.redhat-621084 | OData Error Caught by the ODataError route. Cause: org.apache.camel.TypeConversionException: Error during type conversion from type: java.lang.String to the required type: org.apache.camel.component.http.HttpMethods with value PATCH due java.lang.IllegalArgumentException: No enum constant org.apache.camel.component.http.HttpMethods.PATCH