Split binaries

[coolreader18]

Description of Changes

Resolves #1838

Adds a spacetimedb-update multicall binary that proxies to spacetimedb-cli, and makes spacetime run call out to the spacetimedb-standalone binary instead of embedding the whole server in the cli. Functionality for the update binary itself forthcoming in another PR.

Expected complexity level and risk

3 - adds the proxy binary and changes how run works under-the-hood, but the deeper changes will come in the follow-up.

Testing

Describe any testing you've done, and any testing you'd like your reviewers to do,
so that you're confident that all the changes work as expected!

• Smoketests use new proxy binary and work.
• Manually set up a test environment and spacetimedb-update proxied to the cli binary.

[gefjon]

Needs PR description according to template.

[gefjon]

PR description should include what the correct way for a reviewer to invoke the CLI is now. In the past I've been doing cargo run --manifest-path ~/clockworklabs/SpacetimeDB/Cargo.toml -- $@. This appears to not hit the new functionality. Changing the manifest-path to SpaceitmeDB/crates/update/Cargo.toml appears to not exercise the new functionality either, as that binary is looking to be invoked as spacetime. cargo install --path SpacetimeDB/crates/update also does not allow me to test the new functionality, as it installs as spacetimedb-update.

I also notice that you've updated the smoketests to invoke the inner spacetimedb-cli rather than the spacetime wrapper, which concerns me, as it seems the new functionality is untested.

[gefjon]

Looks great, thanks!

[coolreader18]

@bfops @Centril could you review as codeowners?

[bfops]

I would ideally like to confirm that this has been tested on windows and mac before merging, but that feels out of scope for a codeowner review and @gefjon's already approved.

[bfops]

The files I'm a codeowner for look great to me. Thanks for bearing with me @coolreader18.