[Muon] Set DeadTimeCorrection type to None automatically if errors occurs

[Arturs Bekasovs]

If Dead Time Correction couldn't be applied, scientists find it tedious to go and manually set DTC type to be None.

[Arturs Bekasovs]

Refs #8421. Make DTC type be set to None if error occurs.

Changeset: 51abbcdd2cece3a9566f9ce81ca3b18cead4bffe

[Arturs Bekasovs]

Tester:

There is a specific use case when the previous behavior was irritating:

1. Open Muon Analysis interface.
2. Set Dead Time Correction type to "From Disk".
3. Set Dead Time file used to any data file. (Which will produce an error when trying to load Dead Times)
4. Try to load AutoTestData/MUSR00015189.nxs. An error should be thrown. Make sure it's informative enough.
5. Click OK. Dead Time Correction type should be set to None.
6. Now try to click ">" button (next data file). It should be loaded without any problems. Previously, it would throw an error every time you try to load next data file.

[Jay Rainey]

Merge remote-tracking branch 'origin/feature/8421_muon_dtc_none_on_error'

Full changeset: ​5c02104050532c9650a4c598856d64698680c0bb

[Jay Rainey]

It no longer throws an error every time as it is reset after the first exception is thrown.

[Stuart Campbell]

This ticket has been transferred to github issue ​9265