[enhancement] Prompt for Rosetta on fresh M1 macs

[coolaj86]

When we fallback to x64 on Apple M1 we should check if rosetta is installed / prompt to install it:

# See <https://apple.stackexchange.com/q/427970/27465>
if ! arch -arch x86_64 uname -m > /dev/null 2>&1; then
    webi_prompt "Install Rosetta 2? (ctrl+c to cancel, any key to continue)"
    softwareupdate --install-rosetta --agree-to-license
fi

See also https://apple.stackexchange.com/a/427996

[ryanburnette]

What if I want to run my term as arm64?

[coolaj86]

There's a probably a way to have it run only for fallback arch.

[coolaj86]

This is available as part of #768, but not on-by-default. We'll wait for #756 for that.

Closing here and leaving as a checkmark in #756.