feat: Make getInstanceOptions works everywhere

[Crash--]

ATM getInstanceOptions() only works on web application since it reads the content from the DOM. But it'll not work on mobile since the stack can't inject the data in the HTML.

getInstanceOptions should also work in a mobile application by calling the stack to have all the informations injected in the HTML. (mainly goal when writing this issue, knowing if the cozy is flat or nested. This kind of code will not work cozy/cozy-libs@d33345f#diff-81b87cd8e4fade0e86d13fae5c8324c6R26)

also see #586

• subDomainType: need to use capabilities endpoint (https://github.com/cozy/cozy-stack/pull/2226/files)

[Ldoppea]

Example of PR that manually implemented the checking : https://github.com/cozy/cozy-keys-browser/pull/134/files

Note that there was a mention about getCozyUrl() that exists in cozy-stack-client and seems not to be used a lot outside of this library: https://docs.cozy.io/en/cozy-client/api/cozy-stack-client/#getcozyurl

[Crash--]

more up to date issue ? #1381