Add override_archs to macos_command_line_application

[keith]

This allows you to specify that the rule be built for multiple
architectures and produce a fat binary. This is useful to force binaries
to be share-able between Apple Silicon and Intel machines which is
useful for making sure host tools don't invalidate caches.

[keith]

Submitting as an example alternative to bazelbuild/bazel#13461

[keith]

Besides the rule changed here I'm not really sure which you'd want to have this functionality for, so maybe it would be fine to do this and require users to add the attr to each of their tools as opposed to passing the global flag, I'm not sure.

[brentleyjones]

I can see a need for both this and bazelbuild/bazel#13461. This can be used to undo a global setting. I could see the global setting being a very normal thing (enough that I think the default should be both x86 and arm, and you would use the flag to undo it if you didn't need it).

[keith]

Looks like 73c041d will help this use case

[keith]

There is now the universal rule for this instead