feat(parser): Handle a few more use cases of potential count attributes.

[vincentdesmares]

Our original problem is that: due to an upgrade of i18next version and a move to typescript, many of our plural uses-cases using the Trans component do not work anymore.

This pull request answers a few translations that are not taken in account with the current parser.

• count={a.b}
• count={a?.b}
• count={a - 1}
• count={a ? b : c}

Checklist

• only relevant code is changed (make a diff before you submit the PR)
• run tests npm run test
• tests are included
• commit message and code follows the Developer's Certification of Origin

Checklist (for documentation change)

• only relevant documentation part is changed (make a diff before you submit the PR)
• motivation/reason is provided
• commit message and code follows the Developer's Certification of Origin

[vincentdesmares]

@cheton Not sure why the Ci is not starting.

[vincentdesmares]

It looks like the workflow is awaiting approval from a maintainer for the test to run 😢