Update wallets popup

[pablofullana]

Link to design:
https://app.zeplin.io/project/5ada3ed8a22bd68b01144c63/screen/5bd91923075b100a2cff2e68

Preview:

[igorbarinov]

• what if the user is on mobile
• what if the user has metamask/nifty but it's not unlocked
  Also, I don't think we need to show logos. We need to have links to Zendesk with instructions https://poanet.zendesk.com/hc/en-us/categories/360000586593-Wallets
  @SiddigZeidan

[akolotov]

what if the user is on mobile
what if the user has metamask/nifty but it's not unlocked
Also, I don't think we need to show logos. We need to have links to Zendesk with instructions https://poanet.zendesk.com/hc/en-us/categories/360000586593-Wallets

Everything except what if the user is on mobile was addressed in #151.

Will keep this issue opened to test the behavior on the mobile and think of how it should behave there.