FunctorFactory: Fix DisableJIT behaviour and better feedback

- Propagate the owner requesting a functor to FunctorFactory and
  print it in error messages and debug logs.
- Write a .log file next to each .cpp with functors. It contains the
  same lines plus the list algorithms that registered each functor.
  This is a separate file to avoid unnecessary ccache misses.
- The control flow for the functor cache creation case
  (`DisableJIT=True` + `DisableCache=True`) is simplified.
- `DisableJIT=True` will also prevent using an alredy existing .so
   that was made in a previous run with JIT enabled. In practice,
   disabling JIT means that all functors must be found in the cache.
- If JIT is disabled and not all functors are in the cache, the start
  transition will fail and ERROR messages will be printed with complete
  details of the missing functors.
- Add `KeepTemp` property to control whether cpp (and log) files are
  kept when functors are JIT compiled. This replaces controlling that
  behaviour with OutputLevel.