Add missing functions.py in PatchRes

[cmaranes]

When attempting to import the generate_masks function in PatchRes/PatchRes.py, the module PatchRes.functions cannot be found because the file functions.py does not exist. This breaks downstream code that relies on generate_masks for mask generation:

Res-SAM/PatchRes/PatchRes.py

Line 8 in 6803d22

from .functions import generate_masks

Also it is referenced in other scripts:

Res-SAM/PatchRes/ESN_2D_nobatch.py

Line 7 in 6803d22

from .functions import *

I am looking forward to testing the code—seems promising!

[zhouxr6066]

Sorry, will upload it right away.