Add syntask information to SIGUSR2 output. (SYN-10353)

[vEpiphyte]

This exposes additional information about tasks printed to the console. For example:

Stack for <Task pending name='Task-20' coro=<Daemon._onLinkMesg() running at /home/epiphyte/PycharmProjects/synapse/synapse/daemon.py:395> wait_for=<Future pending cb=[Task.task_wakeup()]> cb=[clone.<locals>.taskdone() at /home/epiphyte/PycharmProjects/synapse/synapse/lib/scope.py:220, <1 more>, Task._onTaskDone()]> (most recent call last):
  File "/home/epiphyte/PycharmProjects/synapse/synapse/daemon.py", line 395, in _onLinkMesg
    await func(link, mesg)
Task-20 is a syntask with the following information: iden=4054d100c903840e8a1a1e97fc6765eb name=storm root=None user=a5b9096be499b0151ee52c93585094be username=root
{'query': 'while (true) { $lib.print(`hi {$lib.repr(time, $lib.time.now())}`) '
          '$lib.time.sleep(12) }',
 'view': 'f0b57c61012e26afe3f28452fa04fad8'}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.73%. Comparing base (f3f571f) to head (3365198).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4728   +/-   ##
=======================================
  Coverage   97.73%   97.73%           
=======================================
  Files         298      298           
  Lines       62352    62355    +3     
=======================================
+ Hits        60941    60944    +3     
  Misses       1411     1411           

Flag	Coverage Δ
linux	97.65% <100.00%> (-0.02%)	⬇️
linux_replay	93.41% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[MichaelSquires]

no tests?

[vEpiphyte]

We don't have any tests for these handlers currently.

[vEpiphyte]

@MichaelSquires I should be able to write quick tests for these functions, mocking builtins.print.