Merge branch 'V2' into V2-eslint-no-empty-object-type

# Description of Changes
There's no current linter running over our TypeScript code, which means
we've got a bunch of dead code and other code smells around with nothing
notifying us. This PR adds ESLint with the typescript-eslint plugin and
enables the recommended settings as a starting point for us.

I've disabled all of the failing rules for the scope of this PR, just to
get linting running without causing a massive diff. I'll follow up with
future PRs that enable the failing rules one by one.

Also updates our version of TypeScript, which introduces a new type
error in the code (which I've had to fix)

frontend/eslint.config.mjs

@@ -27,7 +27,7 @@ export default defineConfig(
         {
           // Allow empty extending interfaces because there's no real reason not to, and it makes it obvious where to put extra attributes in the future
           allowInterfaces: 'with-single-extends',
-        }
+        },
       ],
       "@typescript-eslint/no-explicit-any": "off", // Temporarily disabled until codebase conformant
       "@typescript-eslint/no-require-imports": "off", // Temporarily disabled until codebase conformant