issue #609 TypeScript-Core functionality to verify signatures

[IvanPizhenko]

This PR refactors Typescript part in order to prepare to signature verification functionality.

close #609

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Tests (delete all except exactly one):

• Tests added or updated

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To be filled by reviewers

I have reviewed that this PR... (tick whichever items you personally focused on during this review):

• addresses the issue it closes (if any)
• code is readable and understandable
• is accompanied with tests, or tests are not needed
• is free of vulnerabilities
• is documented clearly and usefully, or doesn't need documentation

[tomholub]

looking good

[tomholub]

checkpoint review, good

[tomholub]

👍

[IvanPizhenko]

So I think I've finished with changes in the code, now just need to test it all.

[IvanPizhenko]

@tomholub Typescript tests passed but Swift tests failed here.

[IvanPizhenko]

Trying to rerun...

[IvanPizhenko]

@tomholub Finally, ready for review, I think.

[tomholub]

Looks great - see comments

[IvanPizhenko]

@tomholub Fixed above notes. Swift test still failing.

[tomholub]

This looks good. Thanks! Since this only updates TS and TS tests pass, I'll force-merge this.

[tomholub]

This looks good. Thanks! Since this only updates TS and TS tests pass, I'll force-merge this.

Actually no - it could still affect the app. I'll set auto-merge, once it's updated from master in a way that passes tests, it should merge.