No indicator for active currency in light mode

[jeromemanzano]

Steps:

1. Go to transfer page
2. There is no indicator for the active currency as show in the photo below.

Proposed Solution:

https://github.com/torusresearch/solana-wallet/blob/13e6c94bcf1bce6b0befa5f2f2f54be9031f1d46/src/pages/wallet/Transfer.vue#L612-L617

.currency-selector {
  @apply py-1 px-4 uppercase text-xs cursor-pointer border-0 text-app-text-500 dark:text-app-text-dark-600;
}

.active-currency {
  @apply dark:bg-app-gray-700 border dark:border-0;
}