Restructure some confusing package paths/names

[Luap99]

Taken from @mtrmac #26394 (review) and I think it is worth to discuss.

Should we change some of the paths instead of documenting them?

• pkg/domain/infra/abi → pkg/engine/local
• pkg/domain/infra/tunnel → pkg/engine/remote
• pkg/bindings → pkg/remote/client
• pkg/api/handlers → pkg/remote/server

or something vaguely like that?

There’s never a good time to make these changes (and, ugh, we would need to have a naming discussion), but just about every time I’m working on Podman, I wish they had already happened, and after a few years of this wish, it gets old.

(Do we have a stable API commitment / external consumers that mean that we can’t, or shouldn’t, rename the packages?)

[Luap99]

pkg/bindings is stable for external consumers, everything else I would be fine with changing.

cc @containers/podman-maintainers

[baude]

We can certainly do this with Podman 6 without these worries imho. I'll follow what people want.