uv-distribution: include all wheels in distribution types (#3595)

Our current flow of data from "simple registry package" to "final
resolved distribution" goes through a number of types:

* `SimpleMetadata` is the API response from a registry that includes all
published versions for a package. Each version has an assortment of
metadata
associated with it.
* `VersionFiles` is the aforementioned metadata. It is split in two: a
group of files for source distributions and a group of files for wheels.
* `PrioritizedDist` collects a subset of the files from `VersionFiles`
to form a selection of the "best" sdist and the "best" wheel for the
current environment.
* `CompatibleDist` is created from a borrowed `PrioritizedDist` that,
perhaps among other things, encapsulates the decision of whether to pick
an sdist or a wheel. (This decision depends both on compatibility and
the action being performed. e.g., When doing installation, a
`CompatibleDist` will sometimes select an sdist over a wheel.)
* `ResolvedDistRef` is like a `ResolvedDist`, but borrows a `Dist`.
* `ResolvedDist` is the almost-final-form of a distribution in a
resolution and is created from a `ResolvedDistRef`.
* `AnnotatedResolvedDist` is a new data type that is the actual final
form of a distribution that a universal lock file cares about. It
bundles a `ResolvedDist` with some metadata needed to generate a lock
file.

One of the requirements of a universal lock file is that we include all
wheels (and maybe all source distributions? but at least one if it's
present) associated with a distribution. But the above flow of data (in
the step from `VersionFiles` to `PrioritizedDist`) drops all wheels
except for the best one.

To remedy this, in this PR, we rejigger `PrioritizedDist`,
`CompatibleDist` and `ResolvedDistRef` so that all wheel data is
preserved. And when a `ResolvedDistRef` is finally turned into a
`ResolvedDist`, we copy all of the wheel data. And finally, we adjust
the `Lock` constructor to read this new data and include it in the lock
file. To make this work, we also modify `RegistryBuiltDist` so that it
can contain one or more wheels instead of just one.

One shortcoming here (called out in the code as a FIXME) is that if a
source distribution is selected as the "best" thing to use (perhaps
there are no compatible wheels), then the wheels won't end up in the
lock file. I plan to fix this in a follow-up PR.

We also aren't totally consistent on source distribution naming.
Sometimes we use `sdist`. Sometimes `source`. Sometimes `source_dist`.
I think it'd be nice to just use `sdist` everywhere, but I do prefer
the type names to be `SourceDist`. And sometimes you want function
names to match the type names (i.e., `from_source_dist`), which in turn
leads to an appearance of inconsistency. I'm open to ideas.

Closes #3351

crates/uv-distribution/src/distribution_database.rs

@@ -173,7 +173,8 @@ impl<'a, Context: BuildContext> DistributionDatabase<'a, Context> {
         }
 
         match dist {
-            BuiltDist::Registry(wheel) => {
+            BuiltDist::Registry(wheels) => {
+                let wheel = wheels.best_wheel();
                 let url = match &wheel.file.url {
                     FileLocation::RelativeUrl(base, url) => {
                         pypi_types::base_url_join_relative(base, url)?