Trading client front-end/design checklist

[wynlim]

For design/front-end to keep track of:

• [x] overall styling pass
• [x] mobile styling pass
• [x] favorite pairs #761
• [x] bid/ask widget #765
• [x] corresponding balance widget #849
• [ ] check default ux states/data in place
• [ ] check entire trading ux flow
• [ ] check error states
• [ ] check tx history
• [x] total payable should be editable #854