feat(i18n): add support for i18next pluralization keys

[whomwah]

Currently the i18n keys typing doesn't support pluralisation as you store the keys with a suffix and target them without [https://www.i18next.com/translation-function/plurals].

Introduced types for plural suffixes and a helper to strip them from keys. This enhances the translation key management in the i18n module.

Checklist

• I have manually tested this, including by generating a new app locally.

Testing

const en = {
  common: {
    ...
    demo_one: "demo",
    demo_other: "demos",
  },
}

translate("common:demo", { count: 1 }) => "demo"
translate("common:demo", { count: 2 }) => "demos"

> yarn run test
yarn run v1.22.22
$ jest
 PASS  app/services/api/apiProblem.test.ts
 PASS  test/i18n.test.ts
 PASS  app/utils/storage/storage.test.ts
 PASS  app/components/Text.test.tsx

Test Suites: 4 passed, 4 total
Tests:       20 passed, 20 total
Snapshots:   0 total
Time:        3 s
Ran all test suites.
✨  Done in 4.37s.

PizzaApp on  main via  v20.13.1 took 4s
> yarn run lint:check
yarn run v1.22.22
$ eslint .
✨  Done in 4.19s.

PizzaApp on  main via  v20.13.1 took 4s
> yarn run compile
yarn run v1.22.22
$ tsc --noEmit -p . --pretty
✨  Done in 2.09s.

[jamonholmgren]

This looks awesome @whomwah! Thank you for the PR.

We'll wait for @mazenchami to get back from paternity leave, as he's the i18n expert here at Infinite Red, but it looks pretty good to me.