binance.venues: add pair-type specific asset keying

Add `bs_src/dst_asset: str` properties which provide for unique keying
into futures vs. spot venues by offering a `.venue: str` property which,
for non-spot delivers normally an expiry suffix (eg. '.PERP') and for
spot just delivers the bair chain-token key.

This enables keying multiple venues with the same mkt pairs easily in
a global flat key->pair table needed as part of supporting a symcache.

piker/brokers/binance/venues.py

@@ -1,8 +1,5 @@
 # piker: trading gear for hackers
-# Copyright (C)
-#   Guillermo Rodriguez (aka ze jefe)
-#   Tyler Goodlet
-#   (in stewardship for pikers)
+# Copyright (C) Tyler Goodlet (in stewardship for pikers)
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
@@ -65,7 +62,7 @@ MarketType = Literal[
     'spot',
     # 'margin',
     'usdtm_futes',
-    # 'coin_futes',
+    # 'coinm_futes',
 ]
 
 
@@ -144,6 +141,13 @@ class SpotPair(Pair, frozen=True):
     def bs_fqme(self) -> str:
         return f'{self.symbol}.SPOT'
 
+    @property
+    def bs_src_asset(self) -> str:
+        return f'{self.quoteAsset}'
+
+    @property
+    def bs_dst_asset(self) -> str:
+        return f'{self.baseAsset}'
 
 
 class FutesPair(Pair):
@@ -176,32 +180,51 @@ class FutesPair(Pair):
         return self.quotePrecision
 
     @property
-    def bs_fqme(self) -> str:
+    def venue(self) -> str:
         symbol: str = self.symbol
         ctype: str = self.contractType
         margin: str = self.marginAsset
 
         match ctype:
             case 'PERPETUAL':
-                return f'{symbol}.{margin}M.PERP'
+                return f'{margin}M.PERP'
 
             case 'CURRENT_QUARTER':
-                pair, _, expiry = symbol.partition('_')
-                return f'{pair}.{margin}M.{expiry}'
+                _, _, expiry = symbol.partition('_')
+                return f'{margin}M.{expiry}'
 
             case '':
                 subtype: list[str] = self.underlyingSubType
                 if not subtype:
                     if self.status == 'PENDING_TRADING':
-                        return f'{symbol}.{margin}M.PENDING'
+                        return f'{margin}M.PENDING'
 
-                match subtype[0]:
-                    case 'DEFI':
-                        return f'{symbol}.{subtype}.PERP'
+                match subtype:
+                    case ['DEFI']:
+                        return f'{subtype[0]}.PERP'
 
         # XXX: yeah no clue then..
-        return f'{symbol}.WTF.PWNED.BBQ'
+        return 'WTF.PWNED.BBQ'
 
+    @property
+    def bs_fqme(self) -> str:
+        symbol: str = self.symbol
+        ctype: str = self.contractType
+        venue: str = self.venue
+
+        match ctype:
+            case 'CURRENT_QUARTER':
+                symbol, _, expiry = symbol.partition('_')
+
+        return f'{symbol}.{venue}'
+
+    @property
+    def bs_src_asset(self) -> str:
+        return f'{self.quoteAsset}'
+
+    @property
+    def bs_dst_asset(self) -> str:
+        return f'{self.baseAsset}.{self.venue}'
 
 
 PAIRTYPES: dict[MarketType, Pair] = {