toJson & fromJson in all platforms for TokenDetails and TokenRequest objects

[mattheworiordan]

Given servers will often issue TokenDetails and TokenRequest objects and then pass these objects to clients on different platforms, it's quite plausible that people will try and encode & decode the attributes manually (which we have seen happen and fail already resulting in https://docs.ably.io/client-lib-development-guide/features/#TE6 being added).

I do not think we should make the implementation of fromJson at the discretion of the lib dev but instead make it a requirement so that we recommend using fromJson in all cases in clients receiving JSON Token* objects.

Then server-side, we should recommend everyone uses a new toJson method that ensures Token* objects are serialized in a portable way regardless of platform.

┆Issue is synchronized with this Jira Task by Unito

[mattheworiordan]

Once this is done, we should add some notes to the docs in regards to recommended approach for serializing and deserializing Token* objects

[sync-by-unito]

➤ Automation for Jira commented:

The link to the corresponding Jira issue is https://ably.atlassian.net/browse/SDK-2835