Better sessions in oauth example

[JonathanWoollett-Light]

Updates the oauth example to use a better approach to session management.

Motivation

The current approach to sessions within the oauth example is not fit for any circumstance, and if anyone where to take it at face value and use async_sessions their application would encounter severe performance issues. The current approach not only fails to lead users down the right path but actively leads them down the wrong path.

Solution

By updating the example to use a viable approach it helps people understand the right way to solve the problem, rather than potentially misleading them.

[mladedav]

Would you mind expanding a bit on the motivation? Is the only issue performance?

[JonathanWoollett-Light]

Would you mind expanding a bit on the motivation? Is the only issue performance?

The main motivation is that the current example while simpler doesn't really give an example of what someone needs to know.

Personally I used this example in testing, but recently discovered that this is not usable in production and thus needed to figure out what was usable. It would've saved me a lot of time if the example was usable to begin with.

I think we can save a lot of people time by simply making the example include what they will need rather than forcing them to look at this example, then realise it can't be used, then find a different example that can be used.