[e.cash] Update the strapi URL

Summary:
It now uses an e.cash URL.

Depends on D18798.
Completes T3904.

Test Plan:

npm run dev

Check the site still works.
Note that CI has been updated accordingly.

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: aimal

Differential Revision: https://reviews.bitcoinabc.org/D18799