Allow switching the current base currency

[sacOO7]

Since a sidechain can have its own sidechains. The DEX UI should allow the user to navigate through the different levels of sidechains.

From the relevant market view, the user should be able to switch to the quote chain as the mainchain so that they can see its sub-markets.

Lisk DEX UI should behave like a file system browser; each market should expose a new layer of sub-markets. In accordance with Leasehold/lisk-dex-ui#1 - After switching to a new base chain, the application should initiate another round of discovery to find additional sub-markets.

The UI should remember the hierarchy of markets so that it can go back up through the different levels back to LSK as the mainchain.

This issue depends on Leasehold/lisk-dex-ui#6 - Users should be able to switch between different markets before they can switch the base currency. The user could select the quote currency from any market as the new base currency.