Translation page text areas don't expand to match other language

## Description
When inputting text in the Translation page for a Form, the _emptier_ text area is reduced in size compared to the original source langauge.

Consider making these the same to reduce noise on the page, and defaulting to the longer one.

## Steps to reproduce
1. Go to GC Forms
2. Create a form
3. Add a few lines of page text to the form in English
5. Switch to "Translations" in the Form set-up right panel
6. See how the English text area is expanded/full in comparison to the French

## Details
- **Browser**: Chrome
- **Operating system**: Mac
- **Environment**: Production
- **Language**: English and French
- **Viewport**: Desktop
- **Output**: cm5gzqaxw00mpaxducnvaky87

## Expected behaviour

Parallel / similar behaviour in both languages

## Screenshots or videos