Improve functionality and consistency of Sanic.event()

[talljosh]

This PR makes the following changes:

• app.event() now takes additional arguments condition and exclusive which behave the same as the same arguments to app.signal()
• blueprint.event() now takes additional argument condition which behaves the same as the same arguments to blueprint.signal()
• app.event() and blueprint.event() now accept an event in enum form as well as str form, consistent with app.signal() and blueprint.signal()
• app.event() and blueprint.event() now return a copy of the context dict passed to app.dispatch() (Signal event to return context #2088)
• blueprint.event() now raises TimeoutError on timeout to be consistent with app.event() (previously, it just silently returned on timeout)
• blueprint.event() now cancels any unfinished wait tasks instead of leaving them waiting
• automatically registered signals no longer raise an error if they are dispatched with context
• fixed Sanic.event() fires when any event in the group is dispatched #2826, where the wrong event was being triggered
• more tests added for signals and events, and some existing tests updated

[codecov]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (4499d2c) 88.191% compared to head (9469f36) 88.219%.

Files	Patch %	Lines
sanic/blueprints.py	72.222%	2 Missing and 3 partials ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #2827       +/-   ##
=============================================
+ Coverage   88.191%   88.219%   +0.028%     
=============================================
  Files           93        93               
  Lines         7232      7275       +43     
  Branches      1242      1249        +7     
=============================================
+ Hits          6378      6418       +40     
- Misses         596       598        +2     
- Partials       258       259        +1     

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