feat(minifront): #1211: remove swap restrictions

Closes #1211

What's done:

extend BalanceSelector to show not only assets with balances but all available assets
fix the issues with empty wallets not rendering a swap block correctly
reduce the height of BalanceSelecor and AssetSelector to 90dvh
auto focus the search inputs in BalanceSelecor and AssetSelector
change validations of the swap input to allow entering any possible values

The balance selector now looks like this:

penumbra-zone / web