Description

Calculating the location of the docs at runtime can generate exceptions if the docs can't be found. They should never not be found, of course, ... but....

Given that development environments are probably the most likely to have this broken and contributor camp is looming, this is a quick and urgent fix to make sure that new contributors don't end up yak-shaving their development environment more than needed.

The commits here:

1. prevent crash on startup if the docs can't be found to be copied around; logging an error if this happens
2. drop an unused _tutorialLocation member that would lead to a crash on startup
3. protect other places the help system is started, having them log an error rather than dump a backtrace to console; these don't actually cause sasview to crash, they are just ugly for the user

How Has This Been Tested?

1. Start sasview and test that view docs still works from both FitPage and Help menu
2. Make loading docs fail by either editing the "docs" entries in sas/system/user.py or by deleting them (from dist-packages/sas if you are working in an editable install as recommended)
3. start sasview, see a log entry on startup and log entries when you attempt to view docs:

ERROR : sas.system.user (user.py:196) :: Documentation could not be found! Help documentation will not be available in SasView.
ERROR : sas.qtgui.Perspectives.Fitting.FittingWidget (FittingWidget.py:1666) :: Help documentation was not found.
ERROR : sas.qtgui.MainWindow.GuiManager (GuiManager.py:361) :: Help documentation was not found.

Review Checklist:

[if using the editor, use [x] in place of [ ] to check a box]

Documentation (check at least one)

• There is nothing that needs documenting
• Documentation changes are in this PR
• There is an issue open for the documentation (link?)

Installers

• There is a chance this will affect the installers, if so
  • Windows installer (GH artifact) has been tested (installed and worked)
  • MacOSX installer (GH artifact) has been tested (installed and worked)
  • Wheels installer (GH artifact) has been tested (installed and worked)

Licensing (untick if necessary)

• The introduced changes comply with SasView license (BSD 3-Clause)