Add rawError to callAPI

[xavdid]

addresses PDE-138

Previously, when the server returned a 400+ error code, we would package the error message up and throw it. This is normally useful, but when we get back a json with errors and want to process them, we were (previously) unable to. It also more correctly identifies when then the issue is an activation one.

This adds a param to callAPI that returns the response object instead of directly throwing an error. This is most relevant in promote, but it will potentially be useful in other places as well. While I was there, I make some of the language more clear too.

Before:

After:

Merging Notes

• This depends on https://github.com/zapier/zapier/pull/16441, so it may not get merged right away.
• this is going to cause a messy merge with Commands that allow a "--format" argument return invalid JSON #247, I'll handle that when we get to it.

[eliangcs]

Pulled and confirmed it works as expected. The code looks good, too!

One minor thing. I see you changed the output message from zapier migrate 1.0.0 1.0.1 [10%] to zapier migrate. Maybe you want to change that in the command help text, too.

[xavdid]

I thought about it, but since that's clearly an example it sort of makes sense to be there. Or if you're more concerned with them matching, i'm happy to.

It would be cool to get some system for keeping the help text and command output in sync. Since the latter happens at runtime it's probably not possible, but it would be useful.

[eliangcs]

@xavdid since the help text is an example output of the command, I thought it'd better if we can keep them in sync. Just #fyi, not a blocker.

[BrunoBernardino]

Looks simple and a great UX improvement! Good job! I didn't pull the code down, though.