[gui] add advancement on the processing

- create core/progress module which contains `Progress` class used to give some feedback about the advancement
- create orangecontrib/progress module to overwrite Progress functions with a QSignal in order to connect this processing to the orange widget.
- this require to move all core processing to classes (ft, exafs...) to keep the 'Progress' or 'QProgress' object
3 jobs for fix_9 in 4 minutes and 32 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed test:python3.5-stretch-pyqt5 #40982

00:04:25

passed test:python3.5-stretch-pyside2 #40983

00:04:24

passed test:test-xas-tutorials #40984

00:04:31