Now that we have plugin support for Chronik, we can build a plugin to index Agora Oneshot offers efficiently.
Using the /utxos endpoint for the Agora plugin, users can basically fetch the equivalent of an orderbook from the blockchain.
There's currently no nice framework for plugins, so for now we e.g. just include all opcodes,D16551 allows us to use the test_framework's CScript class and a hash160 functionll the opcodes.
Depends on D16543We have to add a hash160 function; the current impl requires it to be enabled in OpenSSL, but we might add it from ripemd160.py from the test_framework too at some point, or add a function from Rust.
We also add `Agora` and `AgoraOffer` to `ecash-agora`, allowing easy fetching of offers via the plugin.