Create & use endpoint(s) for chains & tokens

[cristinalare]

values that we need to update & maintain:

1. payoutTokens - needs an endpoint

context:

• we currently have 2 arrays for the hardcoded tokens in /functions/utils.ts : votingTokens and payoutTokens (which are the equal atm)
• we're currently using both: one of them in a file, the other one in another file but this is not needed, we only need to use a single payoutTokens array - we'll have to get that from the indexer probably

2. CHAINS - needs an endpoint

• currently we have a hardcoded array in /functions/utils.ts

3. chain logos - we need to make sure we add the images here that corresponds to a new chain's logo property

• currently located in /public/logos and used like this CHAINS[chainId]?.logo