Fix: Add support to custom t names on custom translation hooks

[guiedugt]

Using custom t names combined with custom translation hooks is not working as expected.
For example, the translation keys will not be extracted:

function MyComponent() {
  const { myTranslationFunction } = useMyTranslationHook('namespace');

  return <p>{myTranslationFunction('myTranslationKey')}</p>;
}

After some investigation, I found this is due to a hardcoded "t" key inside the useTranslationHook extractor:

babel-plugin-i18next-extract/src/extractors/useTranslationHook.ts

Line 59 in 7cc5b80

const tBinding = id.scope.bindings['t'];

This PR adds some simple logic to try out different function names in the order they are defined in the tFunctionNames configuration parameter

[gilbsgilbs]

Sorry for the delay, I completely missed this PR due to personal struggles. I wanted to emphasize that it is very well written and thank you for your contribution. I'll try to publish a release tomorrow after some maintenance chore. Probably a breaking release btw.