Replace uses of hardcoded `address::tokens()` with fetching token addresses from the wallet

[james-chf]

When initially populating the wallet, and when calling anomac balance without specifying a token, we use a hardcoded set of test token addresses.

https://github.com/anoma/namada/blob/26a0b67b22090cdaa5a12cd1b7c6c0ff6d4a56a3/shared/src/types/address.rs#L525-L537

Instead of this hardcoded set, we should delegate to whatever is in the wallet (once we mark out token addresses as in #135 ). When initially populating the wallet, we shouldn't put tokens in there which might not exist - at most only the token(s) that will definitely exist in a chain (XAN/NAM?).

[cwgoes]

@karbyshev can you take this on as part of the wallet work?

[karbyshev]

@tzemanovic Is it still relevant?

[tzemanovic]

@tzemanovic Is it still relevant?

done in #1081