Apply Object member rules even when the methods are overridden

[thomaslevesque]

Prompted by #1774, after internal discussion.

Currently, special fake rules are applied for members of System.Object:

• Equals(object): returns true if the argument is the same instance as the fake
• GetHashCode(): returns the hash code of the fake manager
• ToString(): returns a default string representation of the form Faked <faked object type>

However, when the faked type overrides those methods, these rules are not applied, so a default value is returned instead (unless the methods are explicitly configured). This leads to surprising results:

• Equals always returns false, so the fake isn't even considered equal to itself
• GetHashCode always returns 0
• ToString always returns an empty string

Although this behavior makes sense from a technical point of view, there doesn't seem to be any scenario where it's desirable.

The special rules should still be applied even if the fake type overrides System.Object members.

[afakebot]

This change has been released as part of FakeItEasy 6.2.0.