feat: decode IBC assets sent over multiple channels

[emccorson]

This PR adds support for displaying asset information for IBC assets that have been sent over multiple channels (e.g. Namada -> Cosmos Hub -> Osmosis).

Closes #1219.

Testing

I found it a bit difficult to find live relayers for testing this, but I did get it to work with Namada devnet -> Cosmoshub testnet -> Elys testnet.

1. Transfer some NAM from the internal devnet to Cosmoshub testnet using Namadillo
2. Select "Elys Network" in Namadillo to prompt it to be added to Keplr
3. Transfer the NAM from Cosmoshub testnet to Elys testnet using gaiad (Keplr might work too but I've never tried)
4. Refresh Namadillo and select "Elys Network"
5. Your NAM should appear in the asset list with Namada icon and proper denomination handling.

You can also test by sending other assets between multiple chains if there are live relayers.

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Added

• Decode IBC assets sent over multiple channels
• Add elystestnet temporarily for testing

Fixed

• Fix missing icon for Namada on IBC transfer page.