Always concatenate the default filters with the user-provided filters.
This ensures that when `paths-ignore` is provided,
we begin with the default path inclusions,
not all YAML files.
This makes the `paths-ignore-only` integration test variant
under `filters` pass.
The handling of `paths` is unchanged:
if provided, this overrides the default filters.
Pass the quoted script path to PowerShell using `-File`.
This ensures the path is treated as a string rather
than a command, and correctly handles file paths
that contain spaces, unblocking integration tests.
Add logging to autobuild.cmd for easier debugging.
Quote the paths to the CodeQL CLI dist or autobuild scripts when invoked.
This unblocks integration testing, since our integration tests always use
a CLI with a space in its directory name.
