feat(api): Upgrade to v0.1.5 with improved event subscription API

This update includes the following improvements:
- Version upgraded to 0.1.5
- Added subscribe_events_v2 API with more granular account filtering
- Marked original subscribe_events API as deprecated
- Fixed bug

src/streaming/event_parser/common/mod.rs

@@ -50,6 +50,10 @@ macro_rules! impl_unified_event {
             fn set_transfer_datas(&mut self, transfer_datas: Vec<$crate::streaming::event_parser::common::types::TransferData>) {
                 self.metadata.transfer_datas = transfer_datas;
             }
+
+            fn index(&self) -> String {
+                self.metadata.index.clone()
+            }
         }
     };
 }

src/streaming/event_parser/common/types.rs

@@ -162,6 +162,7 @@ pub struct EventMetadata {
     pub event_type: EventType,
     pub program_id: Pubkey,
     pub transfer_datas: Vec<TransferData>,
+    pub index: String,
 }
 
 impl EventMetadata {
@@ -174,6 +175,7 @@ impl EventMetadata {
         protocol: ProtocolType,
         event_type: EventType,
         program_id: Pubkey,
+        index: String,
     ) -> Self {
         Self {
             id,
@@ -186,6 +188,7 @@ impl EventMetadata {
             event_type,
             program_id,
             transfer_datas: vec![],
+            index,
         }
     }
     pub fn set_id(&mut self, id: String) {