[FEATURE] Add scope analiythis

[Bobronium]

Thesis

pycln should perform scope analythis and remove unused imports accordingly.

Reasoning

This would be consistent with flake8, pylance and PyCharms behaviour in identifying unused imports.

autoflake and unimport are able to remove them as well

cat test.py

import sys

def func():
    import sys

    def inner():
        import sys

        sys.exit(0)

pycln

$ pycln test.py                 
Looks good! ✨ 🍰 ✨
1 file left unchanged.

autoflake

$ autoflake test.py                                                  
--- original/test.py
+++ fixed/test.py
@@ -1,8 +1,7 @@
-import sys
 
 
 def func():
-    import sys
+    pass
 
     def inner():
         import sys

unimport

$ unimport -d test.py           
--- test.py

+++ 

@@ -1,8 +1,6 @@

-import sys
 
 
 def func():
-    import sys
 
     def inner():
         import sys