Don't output ESLint rules that match extended configurations

[JoshuaKGoldberg]

PR Checklist

• Addresses an existing issue: fixes Running twice adds extended configuration's values in output config #447
• That issue was marked as status: accepting prs

Overview

Renames the phrasing of "simplifying" conversion results to "summarizing" them, as the summary actually contains extra information. That information now includes extensionRules so that summarizePackageRules knows the configuration values received from configuration extensions.

Those configuration values are now compared against potentially output ESLint rule configuration. Ones that are directly equal are omitted from the output configuration for being redundant.

[JoshuaKGoldberg]

Hmm, this mostly fixes the general issues, but we now/still have empty objects from configurations getting added to the root output file:

module.exports = {
    "env": {
        "browser": true,
        "es6": true
    },
    "extends": [
        "prettier",
        "prettier/@typescript-eslint",
        "plugin:@typescript-eslint/recommended",
        "plugin:@typescript-eslint/recommended-requiring-type-checking"
    ],
    "ignorePatterns": [],
    "parser": "@typescript-eslint/parser",
    "parserOptions": {
        "project": "tsconfig.json",
        "sourceType": "module"
    },
    "plugins": [
        "@typescript-eslint"
    ],
    "rules": { /* ... */ },
    "settings": {}
};

Note the ignorePatterns and settings. I'll file a followup bug on myself.