[Resolver] Only make the ResolverError include InformativeError inside a command

lib/cocoapods/command.rb

 require 'colored'
 require 'claide'
 
+module Resolver
+  require 'resolver'
+  class ResolverError
+    include CLAide::InformativeError
+  end
+end
+
 module Pod
   class PlainInformative
     include CLAide::InformativeError

lib/cocoapods/resolver.rb

-module Resolver
-  require 'resolver'
-  class ResolverError
-    require 'claide'
-    include CLAide::InformativeError
-  end
-end
-
 module Pod
   class Specification::Set
     class LazySpecification < BasicObject