ADD: Add OPRA.PILLAR stat types

Author: threecgreen

CHANGELOG.md

@@ -15,6 +15,7 @@
   data through the client
 - Added `map_symbols`, `pretty_px`, and `pretty_ts` to `BatchJob` response
 - Added `ARCX.PILLAR.ARCX` publisher
+- Added `ClosePrice` and `NetChange` `StatType`s used in the `OPRA.PILLAR` dataset
 
 ### Breaking changes
 - Remove `default_value` parameter from `Historical::SymbologyResolve`

include/databento/enums.hpp

@@ -233,6 +233,11 @@ enum StatType : std::uint16_t {
   // The volume-weighted average price (VWAP) for a fixing period. `price` will
   // be set.
   FixingPrice = 10,
+  // The last trade price during a trading session. `price` will be set.
+  ClosePrice = 11,
+  // The change in price from the close price of the previous trading session to
+  // the most recent trading session. `price` will be set.
+  NetChange = 12,
 };
 }  // namespace stat_type
 using stat_type::StatType;