feat: Improve error messages in context stack

[ritchie46]

Single context

Ignore the context:

>>> s = pl.DataFrame({"a": [1, 2], "b": [3, 4]}).to_struct()
>>> s.struct.field("c")
---------------------------------------------------------------------------
StructFieldNotFoundError                  Traceback (most recent call last)
Cell In[3], line 3
      1 s = pl.DataFrame({"a": [1, 2], "b": [3, 4]}).to_struct()
----> 3 s.struct.field("c")

File ~/code/polars/py-polars/polars/series/utils.py:107, in call_expr.<locals>.wrapper(self, *args, **kwargs)
    105     expr = getattr(expr, namespace)
    106 f = getattr(expr, func.__name__)
--> 107 return s.to_frame().select_seq(f(*args, **kwargs)).to_series()

File ~/code/polars/py-polars/polars/dataframe/frame.py:7915, in DataFrame.select_seq(self, *exprs, **named_exprs)
   7892 def select_seq(
   7893     self, *exprs: IntoExpr | Iterable[IntoExpr], **named_exprs: IntoExpr
   7894 ) -> DataFrame:
   7895     """
   7896     Select columns from this DataFrame.
   7897 
   (...)
   7913     select
   7914     """
-> 7915     return self.lazy().select_seq(*exprs, **named_exprs).collect(_eager=True)

File ~/code/polars/py-polars/polars/lazyframe/frame.py:1811, in LazyFrame.collect(self, type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, no_optimization, streaming, background, _eager)
   1808 if background:
   1809     return InProcessQuery(ldf.collect_concurrently())
-> 1811 return wrap_df(ldf.collect())

StructFieldNotFoundError: c

Context stack

>>>(
...    pl.scan_csv("does not exist")
...    .filter(pl.col("a") == 3)
...    .explode("bar")
...    .select(pl.col("foo"))
...    .collect()
...)
---------------------------------------------------------------------------
FileNotFoundError                         Traceback (most recent call last)
Cell In[4], line 6
      1 (
      2     pl.scan_csv("does not exist")
      3     .filter(pl.col("a") == 3)
      4     .explode("bar")
      5     .select(pl.col("foo"))
----> 6     .collect()
      7 )

File ~/code/polars/py-polars/polars/lazyframe/frame.py:1811, in LazyFrame.collect(self, type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, no_optimization, streaming, background, _eager)
   1808 if background:
   1809     return InProcessQuery(ldf.collect_concurrently())
-> 1811 return wrap_df(ldf.collect())

FileNotFoundError: No such file or directory (os error 2): does not exist:

This error occurred with the following context stack:
	[1] 'csv scan' failed
	[2] 'filter' input failed to resolve
	[3] 'explode' input failed to resolve
	[4] 'select' input failed to resolve

closes #15880

[stinodego]

Thanks for the quick fix!