[tools/shoestring]: fix pylint error plus add missing test file

problem: pylint error due to too many lines
missing rest-light.json file in sai package
solution: disable pylint error for too many lines
add missing file to the sai package.

---------

Co-authored-by: AnthonyLaw <[email protected]>

Author: Wayonb

tools/shoestring/tests/internal/test_Preparer.py

@@ -28,7 +28,7 @@
 
 
 class PreparerTest(unittest.TestCase):
-	# pylint: disable=too-many-public-methods
+	# pylint: disable=too-many-public-methods,too-many-lines
 
 	# region utils