feat: allow custom ESLint rules and add get-text-anti-pattern

[HowardBraham]

Description

Allows us to write custom ESLint rules directly in our repo, without using an external NPM package.

I evaluated several packages to do this, including:

• https://www.npmjs.com/package/eslint-plugin-local-rules
• https://www.npmjs.com/package/eslint-plugin-rulesdir
• https://www.npmjs.com/package/eslint-plugin-local

eslint-plugin-rulesdir seemed the best for our purposes. I tried for several days to get this working with TypeScript rules, involving @davidmurdoch and @naugtur, but I think it's not going to play nice with LavaMoat. When we upgrade to ESLint 9, we can get rid of eslint-plugin-rulesdir, start using the special "local" plugin, and write TypeScript rules.

get-text-anti-pattern.js serves as an example rule. It's something I've been thinking about for months, for how to combat this prevalent anti-pattern #19870. I don't think this rule is quite good enough yet.

Related issues

Manual testing steps

Screenshots/Recordings

Pre-merge author checklist

• [x] I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• [x] I've completed the PR template to the best of my ability
• [x] I’ve included tests if applicable
• [x] I’ve documented my code using JSDoc format if applicable
• [x] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• [ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• [ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.