Replace i18n by a custom implementation

[vjeux]

There are two problems with the current localization strategy:

• We download the translations on-demand, which means that it does a serial roundtrip for nothing.
• withTranslation helper actually renders the app 3 times on startup, instead of once (I haven't tried to debug it)

This removes all the i18n requires except for the one that does language detection.

Test Plan:

• Make sure that browser language detection works (it sets it to French for me)
• Change the language and make sure it changes all the strings in the UI
• Get a link and make sure that {{url}} is properly replaced
• Refresh the page, make sure that the last set language is still set

[vercel]

This pull request is being automatically deployed with ZEIT Now (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://zeit.co/vjeux/excalidraw/gw5b5yo2w
✅ Preview: https://excalidraw-git-fork-vjeux-removei18n.vjeux.now.sh

[lipis]

Works nicely! One thing though.. do we have to change that as well maybe?

[vjeux]

I'm going to leave the html tag as is for now. I have no idea how it's being used at runtime.