Handle all shells’ de/activation

[flying-sheep]

Fixes #138

This adds shell activation for

• gitbash
• wsl
• ksh
• tcshell
• xonsh
• nushell

and fixes shell activation for C shell.

it also makes sure that it’s impossible to add a terminal to the enum without also adding shell activation/deactivation commands by using a Record type that needs to be exhaustive.

[karthiknadig]

Thanks for the PR! Love the new shell command handling.

[anthonykim1]

Thanks for doing this @flying-sheep
I mentioned #116, we should eventually start using shell type API.

The list on https://github.com/microsoft/vscode/blob/e8346324cfb8b5d680ad657bb67153eb838aebc5/src/vscode-dts/vscode.proposed.terminalShellType.d.ts are subject to change, so feel free to let me know if anyone thinks more shell types could be added to make the workload easier on the extension side. As we want to make sure to cover extensive list of shell types for their specific activation.