Setting versions locally towards 2.0 release

[gnunicorn]

In order to allow to publish, path-dependencies must have a matching version specified, too. This PR attempts to make us ready for a 2.0 releasing to crates by :

• cleaning up the path-definitions, move the version to the front and path to last place in all Cargo.toml
• set the version on all path-defined dependencies
• put sc-network and *consensus* versions into 0.8.0, incl pallet-aura and pallet-babe
• bump other pallets to 2.0

refs #4099

[tomusdrw]

Looks good, but it seems that some versions are still missing.

[gavofyork]

why set versions as well as path? it's just redundant additional tedious data to maintain isn't it?

[gnunicorn]

Unfortunately, defining the version is a requirement to publish on crates.io. Cargo doesn't have any publish --all and won't resolve path to figure out which version to use–in general its publishing helper for workspaces are pretty rudimentary. On the other side path is obviously a lot easier and nicer for development.

Fortunately, because cargo uses semver this isn't much of a deal. We can just define version = "2.0.0" and even if we bump the minor or patch version of that crate to make a new release, this doesn't need any update on this crate. Cargo just will figure out the best version on cargo update (or cargo build if first time). Our internal Cargo.lock will also update without problems. This also allows us to do version updates more independently per crate, like updating network and consensus and apply the changes to the crates that follow without having to publish a breaking change on these, if those dependencies don't alter their externally perceived API.

Having both is the common way to stay sane, and is what we do in the libp2p workspace repo and common practice on other workspace repos, too.

[gavofyork]

👍