Add two menu actions to fetch aliases from https://alias.etokens.cash and add them to contacts. It can be reached via the main application menu (Wallet > Contacts) or in the context menu in the Contacts tab.
This will allow users to type in an alias in the "Pay to" field in the send tab, with autocompletion.
This assumes that for now aliases are immutable (phase 1 aliases). If this changes, we will have to check and update dynamically the alias when the user tries to send money to it.
For now the feature is gated by an activation flag --enable-aliases.
ref T3298