BUG: Series.str.__getitem__ in modin ends up with incorrect dtype if an invalid key was passed

[dchigarev]

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Reproducible Example

import pandas
import modin.pandas as pd

pd_ser = pandas.Series(["a", "b"])
md_ser = pd.Series(["a", "b"])

md_res = md_ser.str[100] # will result into a series full of NaNs
pd_res = pd_ser.str[100] # will result into a series full of NaNs

print(f"modin dtypes:\n{md_res.dtypes}\n") # object
print(f"pandas dtypes:\n{pd_res.dtypes}\n") # float64

print(f"modin internal dtypes:\n{md_res._to_pandas().dtypes}") # float64 (doesn't match modin's cache)

Issue Description

When an invalid key is passed it results into a Series full of NaNs having float64 dtype. Modin on its turn doesn't have this logic of changing the dtype depending on the result and just copies them from the source frame:

modin/modin/core/storage_formats/pandas/query_compiler.py

Lines 1629 to 1631 in 7f12953

	str___getitem__ = Map.register(
	_str_map("__getitem__"), dtypes="copy", shape_hint="column"
	)

Expected Behavior

To work as pandas

Error Logs

Replace this line with the error backtrace (if applicable).

Installed Versions

Replace this line with the output of pd.show_versions()

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Note: this issue is part of an epic #3804