fix: use clean code style method ordering

[ferranpm]

What is the goal?

After realising that the Obsession/MethodOrder cop prefers this order

def method_a; method_c; end
def method_c; 42; end
def method_b; method_c; end # We would expect method_c to appear under method_b

To this one

def method_a; method_c; end
def method_b; method_c; end
def method_c; 42; end

We wrote this PR in order to be able to configure it
We want to favour the method order described in Clean Code, so we're changing the configuration

Is this a restricting or expanding change?

Restricting, although following the previous idea for adding this cop

References

• Related pull-requests: Improve method ordering for methods called by multiple methods jeromedalbert/rubocop-obsession#11

How is it being implemented?

• Add the new configuration flag