SG-21701 Replace instances of Shotgun strings in .py files in all tk-…

[zamu5]

…* repos with "SG"

[hound]

Some files could not be reviewed due to errors:

Traceback (most recent call last):

Traceback (most recent call last):
  File "/home/linters/.local/bin/flake8", line 5, in 
    from flake8.main.cli import main
ModuleNotFoundError: No module named 'flake8'

[jfboismenu]

May I suggest a small change in order to make sure we remain backward compatible?

[hound]

continuation line over-indented for hanging indent
line break after binary operator

[hound]

Black would make changes.