task/runner: Several reliability improvements

[victorges]

This is to make several reliability improvemenets towards the 12/16 launch milestone.

Included changes:

• Handle 429 errors from the API and backoff task execution
• Make our panic handling logic as resilient as possible, using a different flow for sending events
• Update go-api-client and livepeer-data for reliabiltiy improvements (better panic handling, strong consistency for assets/tasks, etc)
• Setup dead lettering for unprocessable messages received from Rabbit. We will need to create new queues because DLX argument is not mutable, so I've also added the "clean up old queue" logic to be used during the rollout (basically deploy, move messages from old queues to new queues, then delete empty old queues manually)
• Publish all messages with a separate timeout from the surrounding context and also with mandatory: true (although later I realized that to get full benefits we need more logic in the AMQP producer)

[codecov]

Codecov Report

Merging #95 (7f5719d) into main (f782ca2) will decrease coverage by 33.19472%.
The diff coverage is 18.01802%.

❗ Current head 7f5719d differs from pull request most recent head 507638e. Consider uploading reports for the commit 507638e to get more accurate results

@@                 Coverage Diff                 @@
##                main        #95          +/-   ##
===================================================
- Coverage   38.64734%   5.45262%   -33.19472%     
===================================================
  Files              3         14          +11     
  Lines            207       1889        +1682     
===================================================
+ Hits              80        103          +23     
- Misses           119       1777        +1658     
- Partials           8          9           +1     

Impacted Files	Coverage Δ
clients/catalyst.go	94.82759% <ø> (ø)
task/prepare.go	0.00000% <0.00000%> (ø)
task/transcode.go	1.29310% <0.00000%> (ø)
task/upload.go	0.00000% <0.00000%> (ø)
task/runner.go	5.34759% <19.80198%> (ø)
task/export.go	0.00000% <0.00000%> (ø)
task/paths.go	0.00000% <0.00000%> (ø)
... and 6 more

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Impacted Files	Coverage Δ
clients/catalyst.go	94.82759% <ø> (ø)
task/prepare.go	0.00000% <0.00000%> (ø)
task/transcode.go	1.29310% <0.00000%> (ø)
task/upload.go	0.00000% <0.00000%> (ø)
task/runner.go	5.34759% <19.80198%> (ø)
task/export.go	0.00000% <0.00000%> (ø)
task/paths.go	0.00000% <0.00000%> (ø)
... and 6 more