Squish Tests: Experiment setup general

As a developer I would like to verify the following behaviour using Squish:

- In the `DAE` perspective, in the `Experiment Setup` tab:
- Select a new time channel file and without clicking `Apply` verify that the current file does not change.
- Select a new time channel file and click `Apply`. Verify that the current file is set.
- In the `DAE` perspective, in the `Data Acquisition` tab:
- Select a new wiring/detector/spectra table file and without clicking `Apply` verify that the current files do not change.
- Select a new wiring/detector/spectra table file and click `Apply`. Verify that the current files are set.
- In the `DAE` perspective, in the `Periods` tab:
- Select a new period file and without clicking `Apply` verify that the current file does not change.
- Select a new period file and click `Apply`. Verify that the current file is set.

#### Additional info:
Refactor the test `tst_can_set_wiring_tables` as it verifies some of the behaviour to be tested.