## Summary
This PR has breadth, but not depth. This adds 3 new `eslint` rules. The
first two protect against the use of code generated from strings (`eval`
and friends), which will not work client-side due to our CSP, and is not
something we wish to support server-side. The last rule aims to prevent
a subtle class of bugs, and to defend against a subset of prototype
pollution exploits:
- `no-new-func` to be compliant with our CSP, and to prevent code
execution from strings server-side:
https://eslint.org/docs/latest/rules/no-new-func
- `no-implied-eval` to be compliant with our CSP, and to prevent code
execution from strings server-side:
https://eslint.org/docs/latest/rules/no-implied-eval. Note that this
function implies that it prevents no-new-func, but I don't see [test
cases](https://github.com/eslint/eslint/blob/main/tests/lib/rules/no-implied-eval.js)
covering this behavior, so I think we should play it safe and enable
both rules.
- `no-prototype-builtins` to prevent accessing shadowed properties:
https://eslint.org/docs/latest/rules/no-prototype-builtins
In order to be compliant with `no-prototype-builtins`, I've migrated all
usages and variants of `Object.hasOwnProperty` to use the newer
[`Object.hasOwn`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn).
