fix(codegen): ensure unique c++ variable names to avoid collision for properties with the same name

[mfazekas]

Summary:

Fixes: #53839

Codegen uses object propertyNames as variable names. This breaks if the same property names appears at multiple levels. Also breaks if a property is called payload as payload is a variable name already used.

Before the fix codegen could generate code like this:

payload.setProperty(runtime, "payload", payload);

Changelog:

[GENERAL] [FIXED] - Fix Codegen to use unique variable names to avoid name collisions in corner cases

Test Plan:

• jest snapshot tests