[Cashtab] change hover text for wallet mgmt icons

Summary: Right now, hovertext for icon that allows user to rename wallets instead says "create." Hovertext for icon that allows users to delete wallets says "Trash." This diff amends to be more clear about the functionality of these icons.

Test Plan: npm test

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D9177