[Feature] LLM-based reconciliation

[dgarijo]

Now that we have somef extracting many fields from many files, I would like to explore using small, local LLMs (based on Ollama) for the following:

• Specific field metadata extraction. In particular, extended descriptions. Maybe installation instructions too.
• Author reconciliation (especially when the same information is in multiple sources)
• Requirement improvement (in particular when we have ranges or versions across multiple files)

Note:

• The LLM-based approach must be optional, as the framework is aimed to be lightweight.
• We need to have the basic functionality in somef-core, have it released as a package and imported here.