SymbolResolver incorrectly resolves unbound local variable

[KuechA]

The SymbolResolver resolves local variables in the same scope even if the first assignment to this variable occurs after a usage. E.g. in python, this leads to an UnboundLocalError.

Example code causing this issue which is currently not implemented accordingly in the CPG (see https://github.com/Fraunhofer-AISEC/cpg/blob/ak/python-comprehension-scope/cpg-language-python/src/test/resources/python/comprehension.py#L70 and for the test see https://github.com/Fraunhofer-AISEC/cpg/blob/ak/python-comprehension-scope/cpg-language-python/src/test/kotlin/de/fraunhofer/aisec/cpg/frontends/python/CollectionComprehensionTest.kt#L1385):

def comprehension_with_list_assignment_and_index_variable_reversed():
    b = [0, 1, 2]
    a = 1
    [a for (b[a], a) in [('this', 0), ('is', 1), ('fun', 2)]] # This crashes because the "a" in the tuple shadows the outer variable and "UnboundLocalError: cannot access local variable 'a' where it is not associated with a value".
    print(b) # prints nothing due to crash

Note: This is not to be confused with a variable which has not been declared (yet) within the scope/context.

          I would say that `refersTo` should be null. I think we did that in other cases where we have an unbound error as well

Originally posted by @oxisto in #2019 (comment)

[KuechA]

We should identify further cases which can cause such behavior and add respective test cases (I didn't find anything suitable in the python language module on a first glance)