Fix bug filling most recent sessions for funds

Fixes bug where `base.fill_reindexed_daily` was forward filling
prices for the most recent sessions of a fund even if those
sessions would not be expected to have prices available given
long delays in publishing price data (which for some funds can
stretch to various days).

With fix, `base.fill_reindexed_daily` now looks at sesions prior to
the most recent whenever the most recent (or prior) session
would not be expected to have price data yet available.

src/market_prices/prices/base.py

@@ -179,10 +179,20 @@ def fill_reindexed_daily(
     if not na_rows.any():
         return df, warnings
 
-    if na_rows.iloc[-1] and helpers.now() <= cal.session_open(df.index[-1]) + delay:
-        na_rows.iloc[-1] = False
-        if not na_rows.any():
-            return df, warnings
+    # do not fill prices for any most recent sessions for which prices would not be
+    # expected to be available. NB this considers more than one session as for some
+    # funds prices many not be available for a number of days (in which case can pass
+    # the corresponding delay as a very high value).
+    i = 1
+    len_df = len(df)
+    while i <= len_df:
+        if na_rows.iloc[-i] and helpers.now() <= cal.session_open(df.index[-i]) + delay:
+            na_rows.iloc[-i] = False
+            if not na_rows.any():
+                return df, warnings
+        else:
+            break
+        i += 1
 
     # fill
     adj_close = df["close"].ffill()