Full diff issue

[JamieC2002]

Closes #10863

Resolved issue in Full DIff Output with string lists where strings that were implicitly concatenated/long strings were treated broken up into multiple strings, causing the output format to be misleading. Now, implicitly concatenated strings/long strings are treated as one string, and the output is consistent with other scenarios involving strings.

Test case:

def test() -> None:
 // Implicit concatenated string 
 ex = [
     "This is some dummy test which shows the strange way in which Pycharm"
     " displays the full diff."
 ]
 assert ex == []

Before:

string in ex is output as two strings.

After:

string in ex is now output as one string.

Worked with @kayliny02.