[orangecontrib] normalization work

- 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
4 jobs for orange_normalization in 4 minutes and 51 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #45548
test:python3.5-stretch-pyqt5_larch

00:02:35

passed #45547
test:python3.5-stretch-pyqt5_pymca

00:04:27

passed #45549
test:python3.5-stretch-pyqt5_pymca_larch

00:04:50

passed #45550
test:test-xas-tutorials_pymca

00:03:17