IDEA-CR-48018: inline function refactoring for python (PY-21287)

- ability to inline single/all invocations and keep/remove the declaration
- handled name conflicts of local and imported vars/functions
- cases when this refactoring is not applicable can be found in PyInlineFunctionHandler

(cherry picked from commit 40e298ba2b833a4408ee774628b84fe422468b91)

GitOrigin-RevId: dd3fab59800163b4f300b410cd28a62c1ee1b6f3

python/testData/refactoring/inlineFunction/simple/main.after.py

@@ -0,0 +1,7 @@
+def foo(arg):
+    local = arg + arg
+    return local
+
+
+local = 42 + 42
+x = local