feature: Give users a way to manage timeouts from inside host functions

[zshipko]

Since host functions can't actually be interrupted, it might make sense to not include them in the overall timeout. If we do that we could then give the user some more fine grained controls for managing timeout from within host functions.

[neuronicnobody]

Also consider removing the default timeout

[zshipko]

Default timeout has been removed in: #641

Still working through some ideas in this branch: https://github.com/extism/extism/tree/extend-timeout

[Simonl9l]

at least from a .Net perspective it would be great to support cancelation tokens ? A how function may call our to other services, that in turn support cancelation, so the cancelation token can be passed along.

I guess that other languages may have similar constructs. The is also related to the need/desire that host functions could could be asynchronous (albeit seem work here was abandoned per the PR: #264) - are there any timelines/plans get back to this?