Add unit tests to System.ComponentModel.Design.Serialization.* components

Add unit tests (if not exists) for

1) Methods:

System.ComponentModel.Design.Serialization.CodeDomSerializer
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializer.#ctor
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializer.Deserialize(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializer.Serialize(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializer.SerializeMember(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object,System.ComponentModel.MemberDescriptor)

System.ComponentModel.Design.Serialization.ExpressionContext
- [ ] M:System.ComponentModel.Design.Serialization.ExpressionContext.get_Expression
- [ ] M:System.ComponentModel.Design.Serialization.ExpressionContext.get_PresetValue

System.ComponentModel.Design.Serialization.CodeDomSerializerBase
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.DeserializeExpression(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.String,System.CodeDom.CodeExpression)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.GetExpression(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.GetUniqueName(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.SerializeCreationExpression(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object,System.Boolean@)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.SerializeEvents(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.CodeDom.CodeStatementCollection,System.Object,System.Attribute[])
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.SerializeProperties(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.CodeDom.CodeStatementCollection,System.Object,System.Attribute[])
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.SerializeToExpression(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object)
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerBase.SetExpression(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object,System.CodeDom.CodeExpression)

System.ComponentModel.Design.Serialization.CodeDomComponentSerializationService
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomComponentSerializationService.#ctor(System.IServiceProvider)

System.ComponentModel.Design.Serialization.CollectionCodeDomSerializer
- [ ] M:System.ComponentModel.Design.Serialization.CollectionCodeDomSerializer.#ctor

System.ComponentModel.Design.Serialization.CodeDomSerializerException
- [ ] M:System.ComponentModel.Design.Serialization.CodeDomSerializerExceptionr.#ctor

System.ComponentModel.Design.Serialization.MemberCodeDomSerializer
- [ ] M:System.ComponentModel.Design.Serialization.MemberCodeDomSerializer.#ctor
- [ ] M:System.ComponentModel.Design.Serialization.MemberCodeDomSerializer.ShouldSerialize(System.ComponentModel.Design.Serialization.IDesignerSerializationManager,System.Object,System.ComponentModel.MemberDescriptor)

2) Classes:

- [ ] System/ComponentModel/Design/Serialization/CodeDomSerializer.cs
- [ ] System/ComponentModel/Design/Serialization/DesignerSerializationManager.cs
- [ ] System/ComponentModel/Design/Serialization/ResourceCodeDomSerializer.cs
- [ ] System/ComponentModel/Design/Serialization/RootContext.cs
- [ ] System/ComponentModel/Design/Serialization/SerializeAbsoluteContext.cs
- [ ] System/ComponentModel/Design/Serialization/StatementContext.cs

Epic: #716
Related issues: #221, #608, https://github.com/dotnet/winforms/issues/10135
Related PRs: #615