Add a Position to EventPositionOpen (#4755)

This is necessary because at no other point in the related chain of
events do we ever see the full position, and we need to see the full
position to get information such as the price.

We could simply add in the price, but it's more conservative to simply
emit the entire position, in case there's anything else we might've
forgotten about.

## Checklist before requesting a review

- [x] If this code contains consensus-breaking changes, I have added the
"consensus-breaking" label. Otherwise, I declare my belief that there
are not consensus-breaking changes, for the following reason:

  > This adds new data to events.

crates/core/component/dex/src/event.rs

@@ -37,6 +37,7 @@ pub fn position_open(position: &Position) -> pb::EventPositionOpen {
         reserves_1: Some(position.reserves.r1.into()),
         reserves_2: Some(position.reserves.r2.into()),
         trading_fee: position.phi.component.fee,
+        position: Some(position.clone().into()),
     }
 }
 

crates/proto/src/gen/penumbra.core.component.dex.v1.rs

@@ -1377,6 +1377,11 @@ pub struct EventPositionOpen {
     /// e.g. 2% fee is expressed as 200, 100% fee is expressed as 10000;
     #[prost(uint32, tag = "5")]
     pub trading_fee: u32,
+    /// The full position.
+    ///
+    /// This is somewhat redundant, but contains any information not present above.
+    #[prost(message, optional, tag = "6")]
+    pub position: ::core::option::Option<Position>,
 }
 impl ::prost::Name for EventPositionOpen {
     const NAME: &'static str = "EventPositionOpen";

crates/proto/src/gen/penumbra.core.component.dex.v1.serde.rs

@@ -2547,6 +2547,9 @@ impl serde::Serialize for EventPositionOpen {
         if self.trading_fee != 0 {
             len += 1;
         }
+        if self.position.is_some() {
+            len += 1;
+        }
         let mut struct_ser = serializer.serialize_struct("penumbra.core.component.dex.v1.EventPositionOpen", len)?;
         if let Some(v) = self.position_id.as_ref() {
             struct_ser.serialize_field("positionId", v)?;
@@ -2563,6 +2566,9 @@ impl serde::Serialize for EventPositionOpen {
         if self.trading_fee != 0 {
             struct_ser.serialize_field("tradingFee", &self.trading_fee)?;
         }
+        if let Some(v) = self.position.as_ref() {
+            struct_ser.serialize_field("position", v)?;
+        }
         struct_ser.end()
     }
 }
@@ -2583,6 +2589,7 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
             "reserves2",
             "trading_fee",
             "tradingFee",
+            "position",
         ];
 
         #[allow(clippy::enum_variant_names)]
@@ -2592,6 +2599,7 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
             Reserves1,
             Reserves2,
             TradingFee,
+            Position,
             __SkipField__,
         }
         impl<'de> serde::Deserialize<'de> for GeneratedField {
@@ -2619,6 +2627,7 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
                             "reserves1" | "reserves_1" => Ok(GeneratedField::Reserves1),
                             "reserves2" | "reserves_2" => Ok(GeneratedField::Reserves2),
                             "tradingFee" | "trading_fee" => Ok(GeneratedField::TradingFee),
+                            "position" => Ok(GeneratedField::Position),
                             _ => Ok(GeneratedField::__SkipField__),
                         }
                     }
@@ -2643,6 +2652,7 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
                 let mut reserves_1__ = None;
                 let mut reserves_2__ = None;
                 let mut trading_fee__ = None;
+                let mut position__ = None;
                 while let Some(k) = map_.next_key()? {
                     match k {
                         GeneratedField::PositionId => {
@@ -2677,6 +2687,12 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
                                 Some(map_.next_value::<::pbjson::private::NumberDeserialize<_>>()?.0)
                             ;
                         }
+                        GeneratedField::Position => {
+                            if position__.is_some() {
+                                return Err(serde::de::Error::duplicate_field("position"));
+                            }
+                            position__ = map_.next_value()?;
+                        }
                         GeneratedField::__SkipField__ => {
                             let _ = map_.next_value::<serde::de::IgnoredAny>()?;
                         }
@@ -2688,6 +2704,7 @@ impl<'de> serde::Deserialize<'de> for EventPositionOpen {
                     reserves_1: reserves_1__,
                     reserves_2: reserves_2__,
                     trading_fee: trading_fee__.unwrap_or_default(),
+                    position: position__,
                 })
             }
         }

proto/penumbra/penumbra/core/component/dex/v1/dex.proto

@@ -655,6 +655,10 @@ message EventPositionOpen {
   // The trading fee for the position, expressed in basis points.
   // e.g. 2% fee is expressed as 200, 100% fee is expressed as 10000;
   uint32 trading_fee = 5;
+  // The full position.
+  //
+  // This is somewhat redundant, but contains any information not present above.
+  Position position = 6;
 }
 
 message EventPositionClose {