Add Bazel query override for scan roots

[brentleyjones]

Summary

• add a --bazel-query option that fully overrides Periphery's default Bazel top-level target query
• only apply --bazel-filter when using the built-in default query
• make the generated Bazel scan aspect follow embedded bundle and plugin edges transitively
• update the Bazel README/changelog entries to document the new query override and transitive scan behavior

Why

This makes it possible to avoid building incorrectly transitioned targets while still analyzing code that is only reachable through app extensions, app clips, watch applications, or Swift compiler plugins.

It also gives callers a straightforward way to exclude targets from the generated scan root set, for example by overriding the query to omit targets tagged manual.

Testing

• swift test on macOS

The local swift test run still had two unrelated pre-existing failures in this environment:

• FilePathGlobTest.testGlobstarWithSlash
• XcodeTargetTest.testSourceFileInGroupWithoutFolder

[brentleyjones]

@ileitch

[ileitch]

It also gives callers a straightforward way to exclude targets from the generated scan root set, for example by overriding the query to omit targets tagged manual.

This could lead to incorrect results if those excluded targets hold references to other targets. The --report-exclude option might be a preferable approach.