Remove all nested waitFor

[nitely]

Chronos does not support nested waitFor and in newer version it fails at compile time when possible. This removes all the waitFor by following this rule:

The way a waitFor is to be removed, is turning the function async (all the way up for caller of callers)
and provide a "sync" version if needed for fully sync paths (one that runs waitFor on it).
A fully sync path is one that is never at any point called inside an async function.
AsyncSpawn is fire and forget, it's not equivalent to waitFor. The equivalent to waitFor inside async is await.