Update toast messages

[erskingardner]

QR code screen

Right now the copy public key button on the QR code screen shows a toast that says "Public Key copied." (Mixed casing and with a period at the end)

It should be "Public key copied"

We should make sure all our toasts follow the same pattern. First letter capitalizes and no punctuation at the end.

keys settings page

On the keys settings page, both toast messages for copying your public and private keys give you a toast message that ends in "to clipboard". We should remove this so it reads "Public|Private key copied", swapping out Public or Private for the right key.

donate settings page

The toasts on copying should be "Copied bitcoin|lightning address"