CAMEL-11919: Salesforce REST API request header...
...s not included in update,upsert,create and query operations
This allows setting Salesforce specific headers on the inbound Camel
message. Supported headers are those that start with `Sforce` or
`x-sfdc` and are need to be of a type that can be converted to a array
of String objects: either String, String[] or collection of String
objects.
Support has been added to set headers on all operations and it is up to
the client to set them in a manner that makes sense for the specific
operation and Salesforce object.
Correspondingly any response `Sforce` headers can now be retrieved from
the outbound message headers.
