Refactor from path 145/245 to path 1899 with migration support

Summary: Implement the new path 1899 for SLPA-aware BCHA wallets

Test Plan:
Do not test this diff with high value wallets

1. Run cashtab locally on the existing master.

git clone git@github.com:Bitcoin-ABC/bitcoin-abc.git
cd bitcoin-abc/web/cashtab
npm i --legacy-peer-deps
npm start

2. If you have real money wallets at the localhost:3000/ instance of Cashtab,

back them up and delete them.

3. Create 2-5 new wallets
4. Send some BCHA and SLPA to these wallets
5. Stop this instance of Cashtab
6. Now, run Cashtab from this diff

arc patch D----
cd web/cashtab/
npm start

7. Observe that BCHA and SLPA balances from legacy wallets exist and are displayed
8. Observe that BCHA/SLPA receiving addresses are now different
9. Send some test BCHA and SLPA transactions
10. Observe that change goes to the new Path1899 addresses

Reviewers: alcipir, majcosta, #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D8765