- complete signature to be `run`
- fix test
- orangecontrib: make inheritance to `Registered` instead of `OWEwoksWidget`
Because `OWEwoksWidget` enforce to use the defined ewokstaskclass which is not something we want for now (avoid task associated with gui, processes on threads...)

- rename `process` to `run` and
- replace output.var_namevar.value by outputs.var_name and input.var_namevar.value by inputs.var_name
- _INPUT_NAMES and _OUTPUT_NAMES where missing (larch processes...)

For now process is always call. When call from workflow_concept it insure the input has benn provided previously. Otherwise you should provide the xas_object. It might evolve with time.

Add some simple unit test to insure an orangecontrib est workflow can be converted to a graph and a graph to an est workflow.
Add test to insure we can execute it as well

Make `Process` inherit from Task
Create a OWESRFWidget which inherit from OWWidget and implement stuff for the task graph.

OWESRFWidget fir the expected design for the esrf task graph. Creating a OWWidgetTaskExecutor for example

- orange signal 'spectra' is renamed xas_obj
- update to the new orange way to define Input and Output
- add a converter widget to convert from xas object to data table

[orangecontrib] rework the display for ft and kweight. kWeight is displaying nothing for the time beeing.

Everything is displayed by ft througt to 'spectrum' display: the window and the ftintensity

Now if a new request is required for processing and the processing thread is running, skip the request. Simplify thing.