Environment variables not set properly on C-Shell

[jessemapel]

ISIS version(s) affected: 3.6.2

Description
Using the conda installation instructions, ISISROOT, ISIS3DATA, and ISIS3TESTDATA are not being set upon activation of the environment

How to reproduce

1. Install ISIS3.6.2 according to the anaconda installation instructions
2. Activate the environment
3. printenv or echo $ISISROOT

Possible Solution
The etc/conda/activate.d/env_vars.sh script does not work in C-Shell because it's exporting from Bash. We need a etc/conda/activate.d/env_vars.csh script. I've hand written one:

#!/bin/csh

# Setup ISIS environment variables
setenv ISISROOT "/usgs/cpkgs/anaconda3_linux/envs/isis3.6.2"
setenv ISIS3DATA "/usgs/cpkgs/isis3/data"
setenv ISIS3TESTDATA "/usgs/cpkgs/isis3/testData"

We also need a /etc/conda/deactivate.d/env_vars.csh script. Here's my hand written one:

#!/bin/csh

# Unset ISIS environment variables
unsetenv ISISROOT
unsetenv ISIS3DATA
unsetenv ISIS3TESTDATA

Additional context
Original bug report by @lwellerastro here. This is an internal post on astrodiscuss so only ASC members can see it, sorry! I've tried to reproduce the relevant parts here.