Track task ownership and visualize

[brson]

Task scheduling is about transferring ~Task pointers. During their lives they travel through many other data structures, including other tasks, the scheduler, shared pipes buffers, I/O callbacks. This is vital information that we should take and use for good.

It should only have a performance impact in debug mode.

[brson]

Even better would be if the integration points needed for this were exposed to a remote debugging protocol.

[thestinger]

Sending exchange allocations is also very relevant performance-wise due to possible false sharing of cache lines.

[flaper87]

triage bump.

[thestinger]

#17325 means this is no longer relevant to the standard libraries.