Consider updating bonsai environment template for better cross-platform support

[ncguilbeault]

It would be useful if the Bonsai Environment template shipped with better cross-platform support. I've been using this Bonsai Linux Environment Template to setup bonsai environments with shell scripts. However, given the fix in #1893, the extra path normalization scripts are no longer necessary, and could be consolidated into a single environment template.

It would be ideal to provide setup scripts that do not require powershell on linux. Personally, I prefer having both powershell and shell scripts in the environment to allow the same repository to be bootstrapped across different OSs, but it could be interesting to have templates initialize differently depending on the OS of the user.

In the Linux template, I also have a useful script for activating the environment, which adds a bonsai alias to the command line for launching the command mono path/to/Bonsai.exe with optional args from anywhere on the system. I would be curious to know if people on Windows would also find an alias like this to be useful and more generally what people think about activating/deactivating bonsai environments.