[new-rule] recommend toThrow matcher for testing against errors (via typechecking)

[G-Rath]

The documentation for toEqual says this:

Note: .toEqual won't perform a deep equality check for two errors. Only the message property of an Error is considered for equality. It is recommended to use the .toThrow matcher for testing against errors.

We should be able to use the typescript-powered type checking to determine if an expect value is an instance of Error, and if so check if the matcher being used is .toThrow.