show fullscreen when create/backup wallet, verify a wallet name before continue

[bugjt]

fixed:

• clicking backup wallet from inside the wallet page should not show the top balance bar #649
• creating new wallet from the exchange page doesn't show full right margins #648
• prevent body of the wallet page from sliding as it causes users to accidentally scroll into another tab #652
• verify a wallet name is available before allowing users to input their seed #665

This PR following changed:

• Show fullscreen when backup wallet
• Show fullscreen when create wallet
• Disable swipe on body of the wallet page
• Verify a wallet name is available before allowing users to input their seed

[JustinBeBoy]

1. need margin title the same setting page

2. remove topbar in mobile and fix margin right

3. Can't switch tab on mobile

4. label's error not disappear after typing

[bugjt]

@JustinBeBoy fixed 1,2,3,4.
2. I think should not hide topbar

[JustinBeBoy]

LGTM