Remove web hosted npm module

Summary: Remove web hosted npm module for SLP transactions and replace with local install

Test Plan:

npm i
npm start

Send a BCHA tx
Send an SLPA tx
Create a wallet
Activate new wallet

npm test

Reviewers: alcipir, #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D8840