This fixes a PropType error when using non-custom slippage, and it
fixes a type inconsistency when custom slippage is used.
Previously, `slippage` was being converted explicitly to a `Number` as
it was passed into `BuildQuote`, but not as it was passed into
`AwaitingSwap`. Also the PropType was set as `string`, despite the fact
that it's a number in most cases, and is used for math.
The PropType has been changed to `number`, and the selective casting to
`Number` has been removed. Instead, the `maxSlippage` value is cast to
a `Number` as it's being selected, so that the type is always
consistent.
The property `quoteDataRows[0]rawNetworkFees` was described as a number
rather than a string. In practice it is a string in all cases. The
PropType and the tests have both been updated to expect it to be a
string.
Sorting was broken for the "Quote Source" column of the quote sort
list. Attempting to sort by this column would arrange the quotes in a
seemingly random order.
It appears that this was due to this column being programmed to sort by
a property called `liquiditySource`, which does not exist in the quote
data. I'm unsure what the difference between `liquiditySource` and
`quoteSource` was supposed to be; the values in the mocks are all
identical.
All references to `liquiditySource` have been updated to refer to
`quoteSource` instead, and the sorting now works correctly.
The `metaMaskFee` property on the "quote data" PropType was not used,
and it never existed in practice. This resulted in PropType errors.
The non-existent property has been removed.
