efl: Change non required constructors to @optional.

Summary:
These constructors aren't checked for in the finalize step of the
initialization and may be given the @optional tag.

For C# this means they can be ommitted from the constructor call.

This also adds `Efl.Ui.View.model` as a constructor of
`Efl.Composite_Model` as the finalizer checks for it.

Fixes T7673

Test Plan: make check

Reviewers: segfaultxavi, zmike, bu5hm4n, cedric, felipealmeida

Reviewed By: segfaultxavi, cedric

Tags: #efl, #do_not_merge

Maniphest Tasks: T7673

Differential Revision: https://phab.enlightenment.org/D7855

src/lib/ecore/efl_composite_model.eo

@@ -31,6 +31,7 @@ class Efl.Composite_Model extends Efl.Loop_Model implements Efl.Ui.View
       Efl.Model.child_del;
    }
    constructors {
-      .index;
+      .index @optional;
+      Efl.Ui.View.model;
    }
 }

src/lib/ecore/efl_view_model.eo

@@ -99,6 +99,6 @@ class Efl.View_Model extends Efl.Composite_Model
       Efl.Model.property { set; get; }
    }
    constructors {
-      Efl.View_Model.children_bind;
+      Efl.View_Model.children_bind @optional;
    }
 }

src/lib/elementary/efl_ui_widget.eo

@@ -595,7 +595,7 @@ abstract Efl.Ui.Widget extends Efl.Canvas.Group implements Efl.Access.Object,
       Efl.Part.part_get; [[Returns @Efl.Ui.Widget_Part.]]
    }
    constructors {
-      .style;
+      .style @optional;
    }
    events {
       moved: Efl.Object; [[Called when widget moved]]

src/lib/elementary/efl_ui_widget_factory.eo

@@ -23,6 +23,6 @@ class Efl.Ui.Widget_Factory extends Efl.Loop_Consumer implements Efl.Ui.Factory
       Efl.Ui.Model.Connect.connect;
    }
    constructors {
-      .item_class;
+      .item_class @optional;
    }
-}
+}

src/lib/elementary/efl_ui_win.eo

@@ -872,9 +872,9 @@ class Efl.Ui.Win extends Efl.Ui.Widget implements Efl.Canvas.Scene, Efl.Access.W
       Efl.Part.part_get;
    }
    constructors {
-      .win_name;
-      .win_type;
-      .accel_preference;
+      .win_name @optional;
+      .win_type @optional;
+      .accel_preference @optional;
    }
    events {
       delete,request: void; [[Called when the window receives a delete request]]

src/lib/elementary/elm_glview.eo

@@ -229,6 +229,6 @@ class Elm.Glview extends Efl.Ui.Widget implements Efl.Gfx.View, Efl.Ui.Legacy
             ]]
    }
    constructors {
-      .version_constructor;
+      .version_constructor @optional;
    }
 }

src/lib/elementary/elm_view_form.eo

@@ -26,6 +26,6 @@ class Elm.View.Form extends Efl.Object
         Efl.Object.destructor;
     }
     constructors {
-        .model_set;
+        .model_set @optional;
     }
 }

src/lib/elementary/elm_view_list.eo

@@ -60,6 +60,6 @@ class Elm.View.List extends Efl.Object
         Efl.Object.destructor;
     }
     constructors {
-        .genlist_set;
+        .genlist_set @optional;
     }
 }