Fixes after ID11 test

• fix pyfai poni parsing
• remove autocompletion
• no default pyfai config
• support different workers
• keep parameters from user and files separate

DEMO_SESSION [2]: user.xrpd_processor
         Out [2]: Parameters:
                   enabled                  True                                                                      
                   workflow                 '/home/denolf/dev/blissoda/src/blissoda/resources/id11/integrate_scan.ows'
                   detector_name            'difflab6'                                                                
                   counter_names            None                                                                      
                   pyfai_config_directory   '/tmp'                                                                    
                   retry_timeout            600                                                                       
                   monitor_name             None                                                                      
                   reference                None                                                                      
                   worker                   None                                                                      
                   integration_options      '... (see below)'                                                         
                  
                  PyFai integration:
                   1. JSON file   '/tmp/difflab6/latest.json'                   
                   2. PONI file   '/tmp/difflab6/latest.poni'                   
                   3. User        {'nbpt_rad': 5000}                            
                   Merged         {'application': 'pyfai-integrate',            
                                   'detector': 'Pilatus1M',                     
                                   'detector_config': {},                       
                                   'dist': 0.05,                                
                                   'error_model': 'hybrid',                     
                                   'extra_options': {'max_iter': 3, 'thres': 0},
                                   'integrator_name': 'sigma_clip_ng',          
                                   'method': 'no_csr_ocl_gpu',                  
                                   'nbpt_rad': 5000,                            
                                   'poni1': 0.1,                                
                                   'poni2': 0.1,                                
                                   'poni_version': 2,                           
                                   'rot1': 0.17453292519943295,                 
                                   'rot2': 0,                                   
                                   'rot3': 0,                                   
                                   'unit': 'q_nm^-1',                           
                                   'version': 2,                                
                                   'wavelength': 1.0332016536100021e-10}