[Cashtab] Add a copy address feature to contact list

Summary: Added copy address along with the rename, send and delete icons in the contact list collapse. Related to T2400.

Test Plan:
cd web/cashtab && npm start
navigate to configure screen
expand contact list collapse
click the Copy button
observe that the contact's address is copied to clipboard
observe the copy success notification

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D11558