go to implementation should find implementation of all sub types transitively.

[heejaechang]

class A:
     def method(self): pass

class B(A):
     def method(self): pass

class C(B):
     def method(self): pass

go to impl or find all impl on A.method should show C.method as well.

also, it should include A.method as well since A.method can have implementation as well unless it is hard as abstract

[rchiodo]

class A:
     def method(self): pass

class B(A):
     def method(self): pass

class C(B):
     def method(self): pass

x = B()
x.method()

Goto impl on x.method should also jump to B.method

[StellaHuang95]

class A:
def method(self): pass

class B(A):
def method(self): pass

class C(B):
def method(self): pass

x = B()
x.method()
Goto impl on x.method should also jump to B.method

Right now for a hierarchy like A->B->C, go to implementation only goes to B and C, I will make the behavior to be it goes to A, B, and C if A is not abstract, and B, C if A is abstract. That should fix this issue.