Allow generic arguments in chain method calls to overflow

[ytmimi]

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Fixes #5249

Previously, we always formatted generic arguments horizontally.

Now, we attempt to format generic items horizontally, but when doing so would lead to issue like exceeding the max_width we format the generic arguments vertically.

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Edit: After doing some backlog triage I found that this would also fix the following:

Closes #3191

[calebcartwright]

I think you're likely heading in the right direction, though remember that we have to remain compliant with style rule prescriptions. Taking a quick glance through the tests I believe what you have so far fails to meet the requirements for the presence of any multi-lined element to require all subsequent elements to be on their own line individually

https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/expressions.md#multi-line-elements

[ytmimi]

Ahh I didn't see that part of the style guide. Thanks for pointing that out 😄. Fingers crossed making the change is a simple enough fix! I know you're a little more familiar with the chain formatting, so I'm wondering if you could point me to where (or explain how) chains know to format all following values vertically?

[calebcartwright]

Actually I may have been doing too much of a drive by and was mistaken. I think the chain layout in your target tests look fine as far as the chain pieces go (suspect I was looking at the source files thinking I was looking at the target), though do want to double check to see if there's potential for any unintended side effects on the arg front

[ytmimi]

Definitely! Take the time you need to properly review the change and if you determine that there's something I'm overlooking here I'd be happy to tweak the implementation.