Use sys.displayhook for converting result to string

[bogdan-nikitin]

Fix for #488

Some libraries, like SymPy, redefine sys.displayhook to change printing behavior.

Use sys.displayhook to convert the result to a string in OutputPrinter._format_result_output.

[CharlesJQuarra]

Just tested this on ubuntu 20.04 / conda 24.9 / python 3.8.18 and it works great. What's the holdup for not merging this?

[CharlesJQuarra]

One observation I have: the output always wraps for me at 78 characters, even if the terminal window is wider than that. If I override num_columns default in sympy.init_printing() and set a higher value, the wrap happens correctly. Not sure if this is a prompt-toolkit issue or sympy, but it only happens using ptpython.repl.embed, not the default REPL

In particular the following solves the wrapping issue for me:

import sympy as sp
from shutil import get_terminal_size

sp.init_printing(num_columns=get_terminal_size()[0])