feat: proxy colony incoming native chain tokens

[iamsamgibbs]

Description

This PR adds native chain token incoming funds - note it does not address any colony native tokens.

The native chain token claims are generated by the fetchColonyNativeFundsClaim lambda, this PR refactors the lambda to also check for balances on any supported chain where a proxy colony has been deployed and return the claims as an array.

I've also temporarily added the chain id on the incoming funds page so we can more easily identify which chain the funds are on whilst we continue development on this feature.

I also began adding a new ProxyToken model, but realised I didn't actually need it to complete the work here, however I've left in place as it will be beneficial for the next few issues.

Testing

• Step 1 - Create a "Manage Supported Chains" action and add proxy chain 1.

• Step 2 - We need to add a new network to your metamask wallet! In the metamask extension, make sure you have the Leela wallet connected in metamask, then open the network select menu.

• Step 3 - Add a custom network

• Step 4 - Give it whatever name and currency symbol you like. Set the RPC URL to 127.0.0.1:8546 and the chain id to 265669101

• Step 5 - Copy the colony address from the dashboard
• Step 6 - In the meta mask extension click "Send"

• Step 7 - Paste the colony address and enter an amount.

If you payment fails, clear the tab data under advanced settings and try again.

• Step 8 - Refresh the colony and navigate to the incoming funds page. You should see the new incoming fund on the proxy chain!

For further testing send more funds (note all native funds are summed together per chain rather than shown as individual claims). Try adding the second proxy chain and sending funds there too.

Diffs

New stuff ✨

• ProxyToken model added

Changes 🏗

• fetchColonyNativeFundsClaim lambda now fetches native chain token balances from other chains

Resolves #3459