Extend primitive conversions and implement TryFrom trait for integer values

[bitzoic]

Description

There have been a number of requests to convert between integer values. This is especially important in some of the recently introduced standards and changes made in the storage optimizations.

This PR extends the primitive conversions to extend values and also implements the TryFrom trait for u64, u32, u16, and u8.

Note: The TryFrom implementations are not included in the prelude and must be imported. The primitive conversions do not need to be imported as they are included in the core.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[SwayStar123]

Looks good otherwise. Just remove all the _u64 and .into_u64() for the as_b256 functions and then move them into the same impl block

[Braqzen]

Why do we have try_as_uX methods and some TryFrom impls? Can we not only use the latter?

[bitzoic]

Why do we have try_as_uX methods and some TryFrom impls? Can we not only use the latter?

These exist prior to the PR in the primitive_conversion.sw file. They will be replaced with TryInto once the trait exists.

[Braqzen]

utACK