Add empty constructors for containers (#3125)

* add empty ctors

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/ActionRowBuilder.cs

@@ -35,6 +35,11 @@ public class ActionRowBuilder : IMessageComponentBuilder, IInteractableComponent
         }
     }
 
+    /// <summary>
+    ///     Initializes a new <see cref="ActionRowBuilder"/>.
+    /// </summary>
+    public ActionRowBuilder() { }
+
     /// <summary>
     ///     Initializes a new <see cref="ActionRowBuilder"/>.
     /// </summary>

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/ComponentBuilderV2.cs

@@ -23,6 +23,11 @@ public class ComponentBuilderV2 : IStaticComponentContainer
         }
     }
 
+    /// <summary>
+    ///     Initializes a new instance of <see cref="ComponentBuilderV2"/>.
+    /// </summary>
+    public ComponentBuilderV2() { }
+
     /// <summary>
     ///     Initializes a new instance of <see cref="ComponentBuilderV2"/>.
     /// </summary>

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/ContainerBuilder.cs

@@ -32,6 +32,11 @@ public class ContainerBuilder : IMessageComponentBuilder, IStaticComponentContai
     /// </summary>
     public bool? IsSpoiler { get; set; }
 
+    /// <summary>
+    ///     Initializes a new <see cref="ContainerBuilder"/>.
+    /// </summary>
+    public ContainerBuilder() { }
+
     /// <summary>
     ///     Initializes a new <see cref="ContainerBuilder"/>.
     /// </summary>

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/SectionBuilder.cs

@@ -38,6 +38,11 @@ public class SectionBuilder : IMessageComponentBuilder, IStaticComponentContaine
         set => _components = value ?? throw new ArgumentNullException(nameof(value), $"{nameof(Components)} cannot be null.");
     }
 
+    /// <summary>
+    ///     Initializes a new <see cref="SectionBuilder"/>.
+    /// </summary>
+    public SectionBuilder() { }
+
     /// <summary>
     ///     Initializes a new <see cref="SectionBuilder"/>.
     /// </summary>