[Cashtab-v2] Fix Tx component width

Summary: Related to task T2339. In cashtab-v2/components/Home/Tx.js, the Txs were not rendering with the correct width. Added width:100% to the TxWrapper styled component to fix this.

Test Plan:
cd web/cashtab-v2 && npm start
observe that the Txs on the home screen are the correct width.

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D11251