[Cashtab] [chronik tx history p19] remove legacy object from tx parsing

Summary:
T2447

Depends on D12147

Remove legacy object. Keep remaining legacy parameters in new parsed object as they are unique and still used.

Test Plan:
Review changes to unit tests and npm test
npm start and txs still render correctly

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D12148