Spike some minimal infrastructure to test inside actual web views

[romaricpascal]

What

Implement minimal apps embedding our review app in a webview so we can test inside an actual app rather than just on the web.

Beyond one from iOS and one from Android, we may want to do a quick research/ask experts about differences between different versions webviews on these OS.

Why

This will help us notice any difference of behaviour when actually embedded inside an app, as well as inform us of any support limitations.

Who needs to work on this

Developers

Who needs to review this

Developers

Done when

• We have a branch with projects running an iOS and Android app embedding our review app inside a webview

[romaricpascal]

Code for an iOS app is available on the spike-css-custom-properties-ios-app branch.