Update exception chaining logic to remove long traceback

[parasj]

@phi-line suggested the raise e from None syntax. I tested it out, and it substantially improves the readability of tracebacks. However, I would like to still raise exceptions from cloud SDKs unmodified. Therefore, I convert those usages from raise e to simply raise which raises cloud exceptions without unnecessary chaining (while preserving chaining within the cloud SDKs).

[parasj]

@phi-line if you have a chance to review, I appreciate your feedback improvements to error reporting.

[phi-line]

I would like to still raise exceptions from cloud SDKs unmodified.

It makes sense to handle cloud SDK exceptions in this way!