Starting with a little sub-sys for tracing caller frames by marking them
with a dunder var (`__runtimeframe__` by default) and then scanning for
that frame such that code that is *calling* our APIs can be reported
easily in logging / tracing output.
New APIs:
- `find_caller_info()` which does the scan and delivers a,
- `CallerInfo` which (attempts) to expose both the runtime frame-info
and frame of the caller func along with `NamespacePath` properties.
Probably going to re-implement the dunder var bit as a decorator later
so we can bind in the literal func-object ref instead of trying to look
it up with `get_class_from_frame()`, since it's kinda hacky/non-general
and def doesn't work for closure funcs..
Tyler Goodlet