Ability to import a CSV contact list previously exported from Cashtab.

1. npm start
2. add a few addresses to the contact list
3. click Export Contacts and save the csv file
4. clear browser cache (backup your seeds)
5. create new wallet, open contact list again and click Import Contacts and choose the csv file exported from Cashtab, and ensure successful population of contacts
6. ensure the open file dialogue only displays the .csv files on the user's local filesystem
7. edit one of the contacts so that the '|' delimiter is contained in their name and export this updated contact list via csv.
8. clear browser cache (backup your seeds)
9. create new wallet, import the csv export from cashtab with a contact name containing the delimiter and ensure the name and addresses are still parsed correctly
10. attempt to import a malformed csv file and ensure error validation notification
11. clear browser cache again
12. import a wallet this time, repeat step 5 and ensure no errors
13. ensure only the New Contact and Import Contacts buttons are rendered on an empty contact list dropdown