node/hack: Print potential USD stablecoins that appear depegged

[djb15]

This addition to the governor token generation script searches for and prints and tokens that look like USD stablecoins and have deviated from the expected $1 price by more than a certain percentage (defaults to 10%). It discards any false positive matches that are specified in an array.

To start with I've only considered USD stablecoins.

Output for the current token list looks something like:

Potentially depegged USD stablecoins (>10%) = 5:
<WH_chain_id>-<WH_token_addr>-<token_symbol> = <token_price>

[
 "2-000000000000000000000000df574c24545e5ffecb9a659c229253d4111d87e1-HUSD = 0.02706502",
 "13-0000000000000000000000005c74070fdea071359b86082bd9f9b3deaafbe32b-KDAI = 0.20189",
 "13-000000000000000000000000754288077d0ff82af7a5317c7cb8c444d421d103-oUSDC = 0.247451",
 "13-000000000000000000000000cee8faf64bb97a73bb51e115aa89c17ffa8dd167-oUSDT = 0.121859",
 "16-000000000000000000000000818ec0a7fe18ff94269904fced6ae3dae6d6dc0b-USDC = 0.092542"
]

To be explicit, this change does not change the output of the generated_mainnet_tokens file, it just outputs to a txt for visibility when reviewing PRs.

[johnsaigle]

I think it might be more robust to match on CoinGecko ID rather than symbol (could do both though), e.g. searching for usd-coin or tether

Doing an exact string match might miss some examples:

(UTF-8 I guess)

{chain: 14, addr: "00000000000000000000000048065fbbe25f71c9282ddf5e1cd6d6a887483d5e", symbol: "USDâ®", coinGeckoId: "tether", decimals: 6, price: 1},

(lowercase T)

{chain: 6, addr: "0000000000000000000000009702230a8ea53601f5cd2dc00fdbc13d4df4a8c7", symbol: "USDt", coinGeckoId: "tether", decimals: 6, price: 1},

(Variant on USDC with some branding)

{chain: 30, addr: "000000000000000000000000d9aaec86b65d86f6a7b5b1b0c42ffa531710b6ca", symbol: "USDbC", coinGeckoId: "bridged-usd-coin-base", decimals: 6, price: 0.998167},  

(no symbol...)

{chain: 1, addr: "b7db4e83eb727f1187bd7a50303f5b4e4e943503da8571ad6564a51131504792", symbol: "", coinGeckoId: "wrapped-usdt-allbridge-from-polygon", decimals: 6, price: 1.004},

[djb15]

Thanks again for the feedback, have tweaked the search to search on "USD" as planned, and added the suggestion to also search on CoinGecko id. Currently there are 13 tokens that match, so not overly noisy, although could probably trim down this list some more by adding some to the exclusion list (don't want to be too strict though as otherwise it defeats the point of this change)