Initial visualization

Summary of Changes

First version of the time-resolved application. It reads a nexus file and plots chunks of time of flight distribution.

The file to test is here: /SNS/users/m2d/tmp/REF_L_211892.nxs.h5

Would be good to make GUI nicer, maybe after this issue is merged, @dugganjw can give it a shot.

Checklist

• The MR has a clear and concise title
• Code is self-documented and follows style guidelines.
• Automated tests are written and pass successfully.
• Regression tests (e.g. manually triggered system tests, manual GUI/tool tests, ...) are performed to make sure the MR does not break anything (when applicable)
• Readme file is present and up-to-date.

Documentation Updates

Additional Notes

Closes #1 (closed)