Plugins: users cannot install plugins on system-wide Workbench installations

[davemfish]

On Windows, if the Workbench was installed for all users on a system, it installs to:
C:\Program Files\InVEST 3.14.2.post387+g366216a2f Workbench

Plugin installation requires writing more data to this location, which users will not have permission to do unless they run the Workbench with admin privs.

Plugin installation will fail with,

Error: Command failed: "C:/Program Files/InVEST 3.14.2.post387+g366216a2f Workbench/resources/miniforge3/condabin/mamba.bat" create --yes --name invest_plugin_schistosomiasis -c conda-forge "python<3.13.0" "gdal>=3.9.0" "setuptools<70" error libmamba Could not open lockfile 'C:\Program Files\InVEST 3.14.2.post387+g366216a2f Workbench\resources\Miniforge3\pkgs\cache\cache.lock'

I'm not sure if it's feasible in this case, but in other cases where the workbench needs to use the filesystem, we typically use someplace in app.getPath('userData'). Could the mamba environment be created in there? An implication of this (good/bad?) is that this data will persist when the Workbench is uninstalled.