feat: implement From on EC structs

[TomAFrench]

Description

Problem*

Resolves

Summary*

I'm experimenting with implementing From and Into now as generic traits are being built out.

Additional Context

Documentation*

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• No documentation needed.
• Documentation included in this PR.
• [Exceptional Case] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[jfecher]

Can we just quietly not include From and Into in Noir? 😅
Unlike other traits where the intent is communicated more clearly, From and Into just read as "cast this thing" and Into doesn't even answer the question of "into what type?" Code using these tends to be more difficult to read than code using normal functions/methods for conversion just to save a few characters at the call site.
I'd rather if we encouraged users to write explicit methods like into_curve or from_field

[TomAFrench]

Interesting, I personally feel the opposite and feel that usage of From results in clearer code compared to a hodge-podge of ad hoc methods all jumbled together in a single impl. Discuss on standup tomorrow?

[TomAFrench]

There's also the fact that we're probably going to end up with an implementation of this trait out in the wild anyway.