Add Rails types for Engine.routes and ActiveRecord::Relation::MULTI_VALUE_METHODS (#931)

* Add Rails types for Engine.routes and https://api.rubyonrails.org/classes/ActiveRecord/Relation.html

* Use `def` for `interface`

```
RBS/Lint/Syntax: unexpected token for interface declaration member, token=`attr_reader` (kATTRREADER)

RBS/Style/EmptyArgument: Insert `()` when empty argument

RBS/Layout/TrailingWhitespace: Trailing whitespace detected.
```

* Review response to #931 (review)

Author: yuzisee

gems/activerecord/6.0/activerecord-6.0.rbs

@@ -158,6 +158,10 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
   def count: () -> ::Integer
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/activerecord/6.1/activerecord-6.1.rbs

@@ -204,6 +204,10 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
   def count: () -> ::Integer
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/activerecord/7.0/activerecord-7.0.rbs

@@ -249,6 +249,10 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
   def sole: () -> Model
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/activerecord/7.1/activerecord-7.1.rbs

@@ -315,6 +315,11 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
   def sole: () -> Model
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
+
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/activerecord/7.2/activerecord-7.2.rbs

@@ -324,6 +324,10 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
   def sole: () -> Model
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/activerecord/8.0/activerecord-8.0.rbs

@@ -324,6 +324,10 @@ interface _ActiveRecord_Relation[Model, PrimaryKey] # rubocop:disable RBS/Lint/T
            | () { (Model) -> boolish } -> ::Integer
            | (Symbol | String column_name) -> ::Integer
   def sole: () -> Model
+
+  def order_values: () -> Array[String | Symbol]?
+  def joins_values: () -> Array[String | Symbol]?
+  def left_outer_joins_values: () -> Array[String | Symbol]?
 end
 
 interface _ActiveRecord_Relation_ClassMethods[Model, Relation, PrimaryKey] # rubocop:disable RBS/Lint/TopLevelInterface

gems/railties/6.0/railties.rbs

@@ -22,7 +22,7 @@ module Rails
   class Engine
     # Defines the routes for this engine. If a block is given to
     # routes, it is appended to the engine.
-    def routes: () ?{ () -> untyped } -> untyped
+    def routes: () ?{ () [self: Mapper] -> void } -> ActionDispatch::Routing::RouteSet
   end
 end