This commit adds a confidence measure to LoadMuonNexus3 algorithm so it can be loaded using the Load algorithm. It also adds a Muon file to the SystemTests data.

This commit adds time correction to the Muon loader. As the histogram data was loaded using the LoadISISNexus algorithm the time zero needed to be applied afterwards.

This commit updates the unit test for the Muon Nexus V2. This was required as the example file has changed since the test was written.

This commit introduces the strategy pattern to which enables the selection of the loading algorithm at run time. In this commit the following functionality is added:
- Structure for strategy pattern.
- Single period loading implementation, which features detector grouping and good frames data calculations.

This commit creates the following:
-LoadMuonNexus3 algorithm
-LoadMuonNexus3Helper file
-LoadMuonNexus3Test file
-Adds a MuonV2 file to the test data
This commit also implements the detector grouping calculation.