xtask: Add release commit creation to release

[zecakeh]

This adds several step:

1. Change the version in the macros crate manifest, if it exists.
2. Change the version in the manifest of crates that depend on the macros crate.
3. Change the version in the crate's manifest.
4. Change the version in the manifest of crates that depend on the crate.
5. Update the changelog of the crate.
6. Ask confirmation for commit with option to see the diff.
7. Commit and push.
8. Continues to publishing and releasing as before.

I changed quite a bit the organisation of the code. The main reason is that we now get all the data for the crates from the cargo metadata result, to avoid having to also parse all the manifests.

The only remaining quirk is the ruma-identifiers-validation crate that won't work with this.

edit(jplatte): resolves #452

[jplatte]

The only remaining quirk is the ruma-identifiers-validation crate that won't work with this.

Since it has an independent version, it can just be handled like a "regular" crate without an associated macro crate.

[jplatte]

First part of review (everything except release.rs)

[zecakeh]

Since it has an independent version, it can just be handled like a "regular" crate without an associated macro crate.

But according to the docs it shouldn't be tagged or released, right?

[jplatte]

Since it has an independent version, it can just be handled like a "regular" crate without an associated macro crate.

But according to the docs it shouldn't be tagged or released, right?

Right. Probably should just be a special case.

[zecakeh]

I'm done with the commits. Ready for review again.

[jplatte]

Looks very good overall, thanks again for working on this!