Finally drop `Symbol`

It was replaced by `MktPair` long ago in,
https://github.com/pikers/piker/pull/489

with follow up for final removal in,
https://github.com/pikers/piker/issues/517

Resolves #517

piker/accounting/__init__.py

@@ -42,7 +42,6 @@ from ._mktinfo import (
     dec_digits,
     digits_to_dec,
     MktPair,
-    Symbol,
     unpack_fqme,
     _derivs as DerivTypes,
 )
@@ -60,7 +59,6 @@ __all__ = [
     'Asset',
     'MktPair',
     'Position',
-    'Symbol',
     'Transaction',
     'TransactionLedger',
     'dec_digits',

piker/accounting/_mktinfo.py

@@ -677,90 +677,3 @@ def unpack_fqme(
         # '.'.join([mkt_ep, venue]),
         suffix,
     )
-
-
-class Symbol(Struct):
-    '''
-    I guess this is some kinda container thing for dealing with
-    all the different meta-data formats from brokers?
-
-    '''
-    key: str
-
-    broker: str = ''
-    venue: str = ''
-
-    # precision descriptors for price and vlm
-    tick_size: Decimal = Decimal('0.01')
-    lot_tick_size: Decimal = Decimal('0.0')
-
-    suffix: str = ''
-    broker_info: dict[str, dict[str, Any]] = {}
-
-    @classmethod
-    def from_fqme(
-        cls,
-        fqsn: str,
-        info: dict[str, Any],
-
-    ) -> Symbol:
-        broker, mktep, venue, suffix = unpack_fqme(fqsn)
-        tick_size = info.get('price_tick_size', 0.01)
-        lot_size = info.get('lot_tick_size', 0.0)
-
-        return Symbol(
-            broker=broker,
-            key=mktep,
-            tick_size=tick_size,
-            lot_tick_size=lot_size,
-            venue=venue,
-            suffix=suffix,
-            broker_info={broker: info},
-        )
-
-    @property
-    def type_key(self) -> str:
-        return list(self.broker_info.values())[0]['asset_type']
-
-    @property
-    def tick_size_digits(self) -> int:
-        return float_digits(self.tick_size)
-
-    @property
-    def lot_size_digits(self) -> int:
-        return float_digits(self.lot_tick_size)
-
-    @property
-    def price_tick(self) -> Decimal:
-        return Decimal(str(self.tick_size))
-
-    @property
-    def size_tick(self) -> Decimal:
-        return Decimal(str(self.lot_tick_size))
-
-    @property
-    def broker(self) -> str:
-        return list(self.broker_info.keys())[0]
-
-    @property
-    def fqme(self) -> str:
-        return maybe_cons_tokens([
-            self.key,  # final "pair name" (eg. qqq[/usd], btcusdt)
-            self.venue,
-            self.suffix,  # includes expiry and other con info
-            self.broker,
-        ])
-
-    def quantize(
-        self,
-        size: float,
-    ) -> Decimal:
-        digits = float_digits(self.lot_tick_size)
-        return Decimal(size).quantize(
-            Decimal(f'1.{"0".ljust(digits, "0")}'),
-            rounding=ROUND_HALF_EVEN
-        )
-
-    # NOTE: when cast to `str` return fqme
-    def __str__(self) -> str:
-        return self.fqme