print error message on gateway for bad request lora errors

[eliteprox]

What does this pull request do? Explain your changes. (required)

This change prints bad request errors from the t2i and i2i pipelines, specifically when LoRa parameters are incorrect or fail to load:

2024/08/26 11:37:46 ERROR text-to-image container returned 400 err="{\"detail\":{\"msg\":\"Error loading LoRas: Error loading LoRas: Unable to load LoRas for adapter 'nerijs/pihxel-art-xl' (RepositoryNotFoundError)\"}}"

2024/08/26 11:35:52 ERROR image-to-image container returned 400 err="{\"detail\":{\"msg\":\"Error loading LoRas: Error loading LoRas: Unable to load LoRas for adapter 'nerijs/pihxel-art-xl' (RepositoryNotFoundError)\"}}"

2024/08/26 11:43:34 ERROR text-to-image container returned 400 err="{\"detail\":{\"msg\":\"Error loading LoRas: Error loading LoRas: Unable to parse '{ \\\"nerijs/pihxel-art-xl\\\" : f }' as JSON.\"}}"

This PR is dependent on livepeer/ai-worker#119

Specific updates (required)

• Updates ai_mediaserver.go to log the error
• Updated ai_process.go prevent retries when LoRa error message returned

How did you test each of these updates (required)

• Tested with invalid LoRa name in both t2i and i2i pipelines
• Tested with invalid LoRa weights in both t2i and i2i pipelines

Does this pull request close any open issues?

AI-501: add-lora-support-to-t2i-and-image-to-image-pipelines

Checklist:

• Read the contribution guide
• make runs successfully
• All tests in ./test.sh pass
• README and other documentation updated
• Pending changelog updated