[Cashtab] [Simplify wallet structure p6] Ensure last final variable calcs match final variable names

Summary:
T2663

Depends on D12659

Per feedback at beginning of this stack, make sure all wallet state variables are defined with their final stored name.

Test Plan: npm test

Reviewers: #bitcoin_abc, kieran709

Reviewed By: #bitcoin_abc, kieran709

Differential Revision: https://reviews.bitcoinabc.org/D12660