RUN_TYPE settings, restart simulations

[evalieungh]

Describe the bug
I'm testing how to restart a simulation after spinup, and suspect the hidden 'restart' option in the RUN_TYPE variable is wrong. The LSP variable is set in the variable config file as read-only and defaults to 'startup'. In the CLM documentation, it looks like 'restart' is not a valid option but rather used when referring to a restart file created from a spinup simulation.

To Reproduce
Steps to reproduce the behavior:

1. Install LSP
2. Change code in resources/config/variables_config.json: set RUN_TYPE to readonly=false
3. get containers up
4. create 'restart' case in GUI
5. case setup fails after submission.

Desktop (please complete the following information):

• OS: linux ubuntu virtual machine on NREC
• Browser Firefox
• Version 1.0.0

Additional context
Suggested fix: remove 'restart' as option, and add 'hybrid' and 'branch', add documentation for how to use it.