Add check to enforce literal syntax for Python builtin types

This check requires authors to initialize empty or zero builtin types
using the literal syntax (e.g., `{}` instead of `dict()`).

Authors may ignore this requirement for certain builtins using the
`--ignore` option.

Authors may also forbid calling `dict()` with keyword arguments
(`dict(a=1, b=2)`) using the `--no-allow-dict-kwargs` flag.

testing/resources/builtin_constructors.py

@@ -0,0 +1,7 @@
+c1 = complex()
+d1 = dict()
+f1 = float()
+i1 = int()
+l1 = list()
+s1 = str()
+t1 = tuple()

testing/resources/builtin_literals.py

@@ -0,0 +1,7 @@
+c1 = 0j
+d1 = {}
+f1 = 0.0
+i1 = 0
+l1 = []
+s1 = ''
+t1 = ()