Add Performance/MinMaxAfterMap rule

[Sija]

This rule is used to identify usage of min/max/minmax calls that follow map.

For example, this is considered invalid:

%w[Alice Bob].map(&.size).min
%w[Alice Bob].map(&.size).max
%w[Alice Bob].map(&.size).minmax

And it should be written as this:

%w[Alice Bob].min_of(&.size)
%w[Alice Bob].max_of(&.size)
%w[Alice Bob].minmax_of(&.size)

[veelenga]

Lgtm