feat(rome_js_formatter): assignment expressions with layout

[ematipico]

Summary

This PR closes #2416

This PR adds Chain and ChainTail to the list of layouts and implements them. I left out on purpose ChainTailArrowFunction to not add too code, mostly because this PR moves code around and it might cause some confusion.

I moved the implementation of write_assignment_like inside the format function of JsAnyAssignmentLike for two important reasons:

• I needed access to JsAnyAssignmentLike variants in order to understand whether a group should be added or not;
• I needed access to the parent of JsAnyAssignmentLike, which was needed for the implementation of the new layout;

I also moved few functions inside the struct itself, because they needed to be exposed. The only loose function is used else where, so I kept there.

Test Plan

I created two new tests for the new layouts, one case where the groups breaks and on where it doesn't.

PR

File Based Average Prettier Similarity: 74.79%
Line Based Average Prettier Similarity: 69.89%

main
File Based Average Prettier Similarity: 74.65%
Line Based Average Prettier Similarity: 69.75%

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Playground for commit 75180cf

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[MichaReiser]

Looking good. Can you add our metrics to the test plan?

[ematipico]

Looking good. Can you add our metrics to the test plan?

Done!