Refactory cryptography util - closes #516

[yatki]

Continuation of this PR: #587

Review checklist

• The PR resolves Refactor cryptography util #516
• All new code is covered with unit tests
• All new code was formatted with Prettier
• Linting passes
• Tests pass
• Commit messages follow the commit guidelines
• Documentation has been added/updated

[shuse2]

I think rc.1 is already out, so i think we can use the latest one

[willclarktech]

This change seems unrelated.

[shuse2]

prettify seems to have some random behavior.
anyone know why?

[yatki]

@willclarktech @shuse2 I realized when you run npm install it formats package.json. I upgraded lisk-elements with npm command thus it introduced this change. I say we should keep this.

[willclarktech]

Ah, with npm v5 it preserves indentation as well I think. OK!

[willclarktech]

LGTM, but I just had a thought: can we remove the util file entirely? It doesn't seem to add much value.

[shuse2]

@willclarktech

LGTM, but I just had a thought: can we remove the util file entirely? It doesn't seem to add much value.

util file u mean this crypto util? I feel the same way.
Only value that i can think of is that it's still external library, so it might be good to have wrapper function in case there are breaking change. (easier to fix)
So how abt remove gradually when migrating?

[willclarktech]

it's still external library, so it might be good to have wrapper

A good point in general, but I don't think we use many of these functions more than once.