Remove hard-coded portal urls

[bent0b0x]

#Problem
We have hard-coded "https://portal.paratii.video" in a few places. This prevents us from, under certain circumstances (e.g. on telegram and probably many more) testing our embeds on staging.

Essentially we embed a video that exists on staging but ultimately the production embed bundle is loaded, and these two will not be compatible (two problems: we load the wrong code and secondly the id from a staging video cannot be found on production).

We should remove these hard-coded urls so that we can test embeds on staging and locally more easily.