Module Todo: Document Metadata

[TheTechromancer]

It would be useful to have a collection of modules that download documents (.pdf, .docx, etc.) and extract useful metadata such as usernames and internal domain names. Thanks to @pjhartlieb and @Sw3d1shPh1sh for requesting.

Would require:

• A module that listens for UNVERIFIED_URLs matching PDF, DOCX, etc., downloads them, and re-raises them as binary blobs
• A module that consumes the binary blobs and extracts metadata

[TheTechromancer]

Note: it would also be nice to emit the text from these documents as an event consumable by excavate, secretsdb, etc.