Overlay: Add script to help maintain overlay annotations

[kaspersv]

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This PR adds a script to automatically add sensible default annotations to files without existing overlay annotations. The script uses naming heuristics to determine which files to annotate. The script adds a module-level overlay[local?] annotation and annotates all non-private inline predicates overlay[caller] for selected files. Maintenance of overlay annotations in already annotated files is not the responsibility of this script and will be handled using QL-for-QL queries. This is intended to allow QL authors to gradually take ownership of overlay annotations and manually add & remove automatically added overlay annotations.

A CI check will be added in a subsequent PR to enforce that the script is run for select languages.

The script is based on @ginsbach's annotation script. However, instead of removing existing overlay annotations, it only annotates files without existing annotations and offloads maintenance of annotated files to QL-for-QL queries.

For https://github.com/github/codeql-core/issues/4951.