If a user mentions a file by name, try to send the whole text with the context (if feasible)

Sometimes a user has a specific file in mind with the query that they want to edit or analyze. For example, I tried this query:

@generate
Recently a user had a problem running appmap-node: they had a script in package.json that read "npm run generate-types & npm run server"; they edited it, inteding to run the server with appmap-node, to "appmap-node npm run generate-types & npm run server". However, this had the effect of only running the generate-types script instrumented, with requests to the server consequently not getting recorded.
Propose changes to the appmap-node.md file that will help users avoid this mistake.

It turns out that in the context, Navie only got bits and pieces of the file in question. The answer wasn't bad, but I can't help but feel it could have been much better if it could see the whole thing. Obviously this won't always be feasible: it might not fit in the context window. However when the user explicitly calls out a file, I feel it should be prioritized to transfer that.

Start by reading the appmap-node.md example and tracing the Navie context-gathering entry point for explicitly named files. The work is done when a named file is prioritized for inclusion when feasible, while respecting the context window; the issue does not name a test to run.