Add individual crate build to CI

[ellie]

We managed to find a situation with the 0.7.0 release where atuin-common would build when built as a dependency of the main atuin crate, however it would not build when built by itself.

This meant it was impossible to publish to crates.io, and the release process could not be completed!

Because of this, CI should test the build of each dependent crate separately to the build of the entire project