Merge new state machines into test branch

See merge request !11

Merging new UI into a test branch

See merge request !10

# Conflicts:
#   .gitlab-ci.yml

Merge branch 'merge_layout_abstraction' of https://ohwr.org/project/hev into merge_layout_abstraction

Merge branch 'merge_layout_abstraction' of https://ohwr.org/project/hev into merge_layout_abstraction

Merge ui_test into ui_dev

See merge request !9

# Conflicts:
#   NativeUI/NativeUI.py

In '[Errno N]' where N is a code, the code number varies across
different devices so can't rely on testing for that.

 Conflicts fixed: NativeUI/NativeUI.py

This reverts commit c6c04f95

This reverts commit 1d425fd2

This reverts commit 7d0e4358

plot and measurement data is now passed from NativeUI to the widgets using signals, rather than widgets calling the get_db methods