- also updated syntax for the condition in the helper script

- complete refactoring of code based on improved logic and better flow handling in exception cases
- changed cvmfs-related helper scripts to always be downloaded regardless of whether CVMFS will be mounted or not
- added documentation for the helper methods used towards the goal of mounting CVMFS on demand
- updated the unmount logic based on the refactored code

for more information, see https://pre-commit.ci

- minor changes (formatting, indentation, improved user facing messages etc.)
- improvements to the existing unmounting process now that mode 3 will
  also be supported
- code refactoring in cvmfs_setup script for better flow and readability
- improvements in cvmfs_helper_funcs to allow for different behaviors as
  a result of using cvmfsexec modes

- fixed a runtime error when concatenating a set with only one element
- added a hyperlink reference to the existing section that outlines the variables related to the on-demand CVMFS provisioning feature
- updated name of the variable (GLIDEIN_WORK_DIR) to specify its usage being internal to
  GWMS
- added `export` command to explicitly export the value of PATH when a
  glidein is reinvoked. This was done to resolve the `pivot_root:
command not found` error