Add balance finder used amplitude event

[begonaalvarezd]

Add balance finder used amplitude event.
Fires when the user clicks on the “Search/Keep searching” button on the Balance Finder screen (under Manage Accounts page) or also when hitting the “Search/Keep searching” button during the Import user flow on the Balance Finder screen

Props:

• accountType: private key | mnemonic | passkey | ledger | keystone | seed