feat: Expand conf, config, perf, and pref

[hippietrail]

Issues

N/A

Description

Expand "conf", "config", "perf", and "pref" to "configuration", "performance", and "preference".

Also covers the plurals "configs", and "prefs".

Also renames ExpandDeref to ExpandDereference for consistency

How Has This Been Tested?

cargo test

I expected cargo test -- xpand to test all Weir and Rust expansion rules, but when it passed I still got failures with cargo test. So I'm missing something.

@elijah-potter It would be great if you can run your fuzzer over this. I have a hunch it will have false positives following . or with _ on either side. If so that will mean we'll either want to add logic for Weir rules never to apply in those contexts, or to expand the scope of strategy beyond Exact and MatchCase - perhaps add context? Or maybe this can already be handled by Weir syntax, in which case feel free to send a PR to this PR (-:

AI Disclosure

• I am a human and didn't use any AI.
• I used LLM features of my editor, but not an agent.
• I used an AI agent interactively.
• I am an agent or I got an agent to do the work autonomously.

If Your PR Implements or Enhances a Linter

• I made up the sentences in the unit tests.
• The sentences in the unit tests were generated by an AI.
• I'm using examples from the bug report / feature request.
• I collected real-world sentences for the unit tests.

Checklist

• I have performed a self-review of my own code
• I have added tests to cover my changes
• I have considered splitting this into smaller pull requests.