Support adding additional parameters to jobs, services etc.

[m-mohr]

Support the additional parameters in create_job, create_service etc. This could then be used to add e.g. the job_options parameter as used by VITO. Unfortunately, the ... parameter in the functions is already used to pass things through to the JSON library. So either er want to split the data depending on whether the parameter is known by the JSON library, and otherwise pass it in the body. Or we add an additional paramater as proposed in the client dev guide and implemented also in the JS client.

Related issue: https://github.com/Open-EO/openeo-api/issues/276 Related forum topic: https://discuss.eodc.eu/t/error-loading-sentinel-3-slstr/395/6