support for simple cache api

[syphar]

I mean "The Compute Simple Cache API.".

Currently I'm seeing errors when I'm trying to use it in integration tests using viceroy-lib

[cceckman-at-fastly]

Hi @syphar , thanks for filing the issue!

The simple cache API is part of the SDK; it uses the same hostcalls (WASM system calls) as the core cache API, i.e. it's a layer on top of the core cache API. So "implement the core cache API" in Viceroy will provide the simple cache API.

I've been working on this support. Once #484 is merged, the simple cache API should be ready for use!

[syphar]

That's awesome, thanks!