Install stellar and soroban CLIs when installing either

[leighmcculloch]

What

Install the stellar and soroban CLI binaries when installing either the stellar-cli or soroban-cli crate.

Why

In short this change is being made to improve the developer experience during the rename of the CLI.

The CLI is transitioning from being the Soroban CLI to the Stellar CLI, and with that the binary is also transitioning from being soroban to stellar. It'll take a while for that rename to reverberate through the community, docs, tutorials, video walkthroughs, etc. During that transition period this rename should be a non-event, uninteresting, boring, and zero impact. For an undetermined (read long) period of time both the stellar-cli and soroban-cli crates will be published so that if someone is following an old tutorial or docs in a blog somewhere, the install instructions will continue to work.

This change takes it step further and makes it so that no matter which crate you install, you get both binaries. This is to help the situation where someone reads an install tutorial and installs the soroban-cli, then reads a newer tutorial that uses the stellar binary, they'll find the example commands work because the soroban-cli installed both. We've already had at least one person in the community fall into this situation where they did the reverse and installed the stellar-cli crate then followed a tutorial that used the soroban binary.

Note that it will be possible to identify which crate a binary was installed from, by running the version subcommand. For either binary, the name displayed will be the name of the crate the binary was installed from.

[janewang]

I'm working on a PR to rename cli in the dev docs. PR is WIP there.