[Enhancement] KCL Semantic model issues for config attribute

[He1pa]

Some issues about KCL semantic model(Scope and ScopeObject now)

1. Missing connection of scope object and it child scope

m = {
    "a" : 1
}

b = m.a

Get a scope object m and a child scope {"a": 1}, but missing connect with them. When try to find definition of m.a:
, first, find the definition of m and get scope object m, and cannot search the child scope and search definition of a.

2. attr scope object

schema Person:
    name?: str = "a"

scope object of name not contains information about optional and default value