Reports invalid usages of NewType.

Examples:

from typing import NewType

InvalidName = NewType("Name", int)  # Variable name 'InvalidName' does not match NewType name 'Name'

from typing import Literal

InvalidType = NewType("InvalidType", Literal[1])  # NewType cannot be used with 'Literal[1]'

Base = NewType("Base", str)

class Derived(Base):  # 'Base' cannot be subclassed
    pass