fix: Prevent webpack loading bindings when importing UTXOInput type

[msarcev]

Description of change

• Moved UTXOInput#fromOutputId static function to lib/index.ts to be attached dynamically.

Prevents webpack loading bindings when just importing UTXOInput type.

Links to any relevant issues

Be sure to reference any related issues by adding fixes #issue_number.

Type of change

Choose a type of change, and delete any options that are not relevant.

• Bug fix (a non-breaking change which fixes an issue)

How the change has been tested

Tested the static function manually with some outputId cases.

Change checklist

Tick the boxes that are relevant to your changes, and delete any items that are not.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked that new and existing unit tests pass locally with my changes

[DaughterOfMars]

I don't think this is the right approach

[DaughterOfMars]

I think this is okay?

[qrayven]

I think this is okay?

I think It's ok because this is technically the only place we import bindings in types, so we won't need similar fixes for other types.