Fix double cancel bug!

Not sure how this lasted so long without complaint (literally since we
added history 1m OHLC it seems; guess it means most backends are pretty
tolerant XD ) but we've been sending 2 cancels per order (dialog) due to
the mirrored lines on each chart: 1s and 1m. This fixes that by
reworking the `OrderMode` methods to be a bit more sane and less
conflated with the graphics (lines) layer.

Deatz:
- add new methods:
  - `.oids_from_lines()` line -> oid extraction,
  - `.cancel_orders()` which makes the order client cancel requests from
    a `oids: list[str]`.
- re-impl `.cancel_all_orders()` and `.cancel_orders_under_cursor()` to
  use the above methods thus fixing the original bug B)

piker/ui/order_mode.py

@@ -31,6 +31,7 @@ from typing import (
 )
 import uuid
 
+from bidict import bidict
 import tractor
 import trio
 from PyQt5.QtCore import Qt
@@ -601,50 +602,65 @@ class OrderMode:
             )
 
     def cancel_orders_under_cursor(self) -> list[str]:
-        return self.cancel_orders_from_lines(
+        return self.cancel_orders(
+            self.oids_from_lines(
                 self.lines.lines_under_cursor()
             )
-
-    def cancel_all_orders(self) -> list[str]:
-        '''
-        Cancel all orders for the current chart.
-
-        '''
-        return self.cancel_orders_from_lines(
-            self.lines.all_lines()
         )
 
-    def cancel_orders_from_lines(
+    def oids_from_lines(
         self,
         lines: list[LevelLine],
 
-    ) -> list[str]:
+    ) -> list[Dialog]:
 
-        ids: list = []
-        if lines:
+        oids: set[str] = set()
+        for line in lines:
+            dialog: Dialog = getattr(line, 'dialog', None)
+            oid: str = dialog.uuid
+            if (
+                dialog
+                and oid not in oids
+            ):
+                oids.add(oid)
+
+        return oids
+
+    def cancel_orders(
+        self,
+        oids: list[str],
+
+    ) -> None:
+        '''
+        Cancel all orders from a list of order ids: `oids`.
+
+        '''
         key = self.multistatus.open_status(
-                f'cancelling {len(lines)} orders',
-                final_msg=f'cancelled {len(lines)} orders',
+            f'cancelling {len(oids)} orders',
+            final_msg=f'cancelled orders:\n{oids}',
             group_key=True
         )
-
-            # cancel all active orders and triggers
-            for line in lines:
-                dialog = getattr(line, 'dialog', None)
-
-                if dialog:
-                    oid = dialog.uuid
-
+        for oid in oids:
+            dialog: Dialog = self.dialogs[oid]
+            self.client.cancel_nowait(uuid=oid)
             cancel_status_close = self.multistatus.open_status(
                 f'cancelling order {oid}',
                 group_key=key,
             )
             dialog.last_status_close = cancel_status_close
 
-                    ids.append(oid)
-                    self.client.cancel_nowait(uuid=oid)
+    def cancel_all_orders(self) -> None:
+        '''
+        Cancel all unique orders / executions by extracting unique
+        order ids from all order lines and then submitting cancel
+        requests for each dialog.
 
-        return ids
+        '''
+        return self.cancel_orders(
+            self.oids_from_lines(
+                self.lines.all_lines()
+            )
+        )
 
     def load_unknown_dialog_from_msg(
         self,
@@ -750,7 +766,7 @@ async def open_order_mode(
         trackers: dict[str, PositionTracker] = {}
 
         # load account names from ``brokers.toml``
-        accounts_def = config.load_accounts(
+        accounts_def: bidict[str, str | None] = config.load_accounts(
             providers=[mkt.broker],
         )
 
@@ -1135,8 +1151,9 @@ async def process_trade_msg(
             action = order.action
             details = msg.brokerd_msg
 
-            # TODO: put the actual exchange timestamp?
-            # TODO: some kinda progress system?
+            # TODO: state tracking:
+            # - put the actual exchange timestamp?
+            # - some kinda progress system?
 
             # NOTE: currently the ``kraken`` openOrders sub
             # doesn't deliver their engine timestamp as part of