TransferHttpCacheModule does not cache Apollo requests

[CDDelta]

Intended outcome:
This is more a docs problem more than anything. The docs include a recipe for using TransferHttpCacheModule to cache requests when using SSR but it does not work as the module does not support POST requests and has no intention to support it. See here. The recipe should be removed.

Actual outcome:
Two requests are performed, one on the server and another on the client.

How to reproduce the issue:
N/A

Versions
Latest

[kamilkisiela]

PR welcome, feel free to change it in the docs.

[CDDelta]

Done here: #1022

[intellix]

Can the recipe not just add method: 'GET' instead of removing? Feel like most people will just assume it's unsupported and not realise they can get it via using GET

[kamilkisiela]

I think that @intellix is right, we shouldn't remove it completely but mention it works only with GET.

I also think it would be awesome to have an ignore pattern or a whitelist in TransferHttpCacheModule because sometimes you know exactly which requests are using POST but not mutating data etc.

[matmeylan]

Is there any workaround to use TransferHttpCacheModule out of the box and transfer http state from SSR to client ? I see no mention of this POST issue in the docs. Or is the store rehydration solution the recommended way to go ?