Invalid addresses are marked as Valid by the UI

[gmale]

Please make sure you have the latest ZecWallet.

Describe the bug Addresses that match this regex are marked as valid by the UI, when in fact they are not valid addresses. At worst, this is merely a UI bug because the transaction builder will reject transactions that involve an invalid address.

To Reproduce Steps to reproduce the behavior:

1. Go to 'Send'
2. Enter an invalid address in the "To" field that is 34 characters long and starts with a t such as thisIsClearlyNotAValidTAddressRight
3. Observe the following incorrect validation:

Expected behavior Expected that the UI would show this is an invalid address

Desktop (please complete the following information):

• OS: Ubuntu and iOS
• Version 20.04

Additional context Initially reported to us by Unstoppable wallet engineers, working on updating the iOS build and confused why a sample zcash t-address pulled from Zcash documentation wasn't working.