Replace uses of assert.Error followed by
assert.Contains on the error message,
with the single-line assert.ErrorContains.

Add a `Level() Level` method on Logger and SugaredLogger
that reports the current minimum enabled log level for the logger.

This relies on the zapcore.LevelOf function added in #1147.

Resolves #1144
Depends on #1147

We should export objectMarshalerPtr since it's exposed in a public
API - ObjectValues[T any, P objectMarshalerPtr[T]].

Ref #994, #1000

Alternate approach to #999, this approach brings absolute path support
to Windows.
It does so by checking for absolute paths and handling them using the
file factory directly.

To test different paths without trying to actually open them (UNC paths
hit the network), this change also
prefactors the sink registry into a separate type that allows stubbing
of the `os.OpenFile` call.

Note: This change does not bring full Windows support -- many tests
still fail, and Windows file URIs don't work.

Some of the doc comments on deprecated APIs weren't formatted correctly
and wasn't showing up as deprecated on pkg.go.dev.

This fixes those incorrectly formatted docs. Also added links to point
to the new APIs that deprecated them.

This release includes the following changes:

[v1.23.0...ed5598a.](v1.23.0...ed5598a)

Refs GO-1752.