[e.cash] Open external links in new tab - mining page

Summary: Using the cusotm link component on the mining page so external links open in a new tab

Test Plan: Preview the site and check the links open in a new tab on the mining page

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D14699