feat: Support Cargo workspace inheritance

[bb010g]

Virtual workspaces are generally less special now. Logging coverage has increased where it was useful during debugging. Switching to Path::strip_prefix from substrings using Path::to_str_lossy has fixed possible confusion when temporary paths are long. Cargo &Package values are carried around longer now so that the user doesn't have to write explicit lib tables into their Cargo.toml files to avoid warnings.

Fixes kbknapp/cargo-outdated#325.

[Xiretza]

This is not enough to fix the following case, where there is a path dependency on a package that is part of a separate workspace:

#!/usr/bin/env bash

mkdir testcrate
cd testcrate

mkdir src && touch src/lib.rs
cat > Cargo.toml <<-EOF
[package]
name = "testcrate"
version = "0.1.0"
edition = "2021"

[dependencies]
ws_member = { path = "ws_dep/ws_member" }
EOF

mkdir ws_dep
cd ws_dep

cat > Cargo.toml <<-EOF
[workspace]
members = ["ws_member"]
resolver = "2"

[workspace.package]
version = "0.1.0"
EOF

mkdir ws_member
cd ws_member

mkdir src && touch src/lib.rs
cat > Cargo.toml <<-EOF
[package]
name = "ws_member"
version.workspace = true
edition = "2021"
EOF

error: cargo update in temp compat workspace for "/tmp/testcrate/Cargo.toml"

Caused by:
  Updating Cargo lockfile

Caused by:
  failed to get `ws_member` as a dependency of package `testcrate v0.1.0 (/tmp/cargo-outdated5rgCOb)`

Caused by:
  failed to load source for dependency `ws_member`

Caused by:
  Unable to update /tmp/cargo-outdated5rgCOb/ws_dep/ws_member

Caused by:
  failed to parse manifest at `/tmp/cargo-outdated5rgCOb/ws_dep/ws_member/Cargo.toml`

Caused by:
  error inheriting `version` from workspace root manifest's `workspace.package.version`

Caused by:
  failed to find a workspace root

The check here needs to be generalized not just for the workspace of the root package, but for all dependency packages.

[Xiretza]

FYI, I've rebased this on master and factored out all the unrelated changes in this branch of mine, you might want to work off that if you continue with this: https://github.com/Xiretza/cargo-outdated/tree/workspace-inheritance

[kbknapp]

@Xiretza and @bb010g thanks for digging into this and sorry for the silence - if you'd like to re-energize this PR I'll help get it included.