Integrated Terminal - Added support Fish Shell

[nis-ship-it]

Description

Add the fish shell to the enums and reading the config.fish only at present.

Related Issues

• #1853

Checklist

• [ ] I read and understood the contributing guide as well as the code of conduct
• [ ] The issues this PR addresses are related to each other
• [ ] My changes generate no new warnings
• [ ] My code builds and runs on my machine
• [ ] My changes are all related to the related issue above
• [ ] I documented my code

Screenshots

[tom-ludwig]

It would be nice if it defaulted to zsh/bash when Fish isn’t available. A small red message in the terminal like Fish shell not found. Defaulting to bash/zsh would be helpful too, but the priority is making sure it defaults to another shell for now.

[ghost]

@tom-ludwig I was thinking also the same switching to zsh since it's by default