[explorer] Hide the advanced transaction data by default

Summary: This contains the tx hex which can be very large and makes navigation more complicated.

Test Plan:

cargo run

Open any transaction page and check the advanced block is now an accordion and folded by default.

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D17893