dart format (and possibly analyze) should fail if it is unable to resolve include references in analysis_options.yaml

[isoos]

SDK: 3.7.0

dart format reads analysis_options.yaml to get the formatter options (e.g. page_width). However, if the include reference inside that file is not available, it throws out the rest of the file too, ignoring the existing formatter options, using only the default values.

Originally found root cause here:
dart-lang/pana#1448

I think this silent fallback on failure is surprising, and I think dart format and possibly dart analyze should fail hard with clear error messages that some reference was not found.