Rounding amounts are different on swap form and confirm modal when 'Max' token value is selected

[elena-zh]

Originally reported and discussed here #1281 (comment)

Low-low priority

Although, more than 4 decimals are considered as an expected behavior when fill in a field with a Max token value, I'd like to mention the next case:
token value is not rounded in the Swap form, however, it appears to be rounded in the confirmation modal

IMO, rounding should be the same..

[alfetopito]

The thing is, on user input there's no rounding. On summary there is.
Also, on summary the title with full amounts is available (on desktop)

[stale]

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