Error on the Firestore viewer when trying to decode URI containing the character '%'.

This bug was found when resolving the [pull request #258](https://github.com/firebase/firebase-tools-ui/pull/258), which encodes and decodes collection and document ids, in order to handle special characters.

The situation is that when an URI has the character '%', it is correctly encoded, but the React library **'history'** automatically decodes only the character '%' and pushes this path to the HTML5 history element. This is a known issue of the library that can be found [here.](https://github.com/ReactTraining/history/issues/505)

Because of this automatic decode issue, the moment the partially encoded URI is tried to be decoded on our code, an error occurs due to malformed URI.