Fixes#670.
Component spec based on https://www.notion.so/emizzle/Wallet-transaction-components-2003b78a8d0d41c4ab3d21eb2496fb20.
Changes the current Select shared component to a model databound component. This means we can bind directly to `QAbstractListModel`'s coming from Nim instead of needing manipulating the data in to javascript objects. The changes to the Select component will be used for the upcoming Asset selector shared component.
emizzle