Add support merge InitialValues

[genusP]

Issue Type

'feature request'

Description

I write custom configuration component implement connect datasource. My source register initial values for editorOptions. For this solution any other options setup over editorOptions prop not apllied. Please add merge options in https://github.com/DevExpress/devextreme-vue/blob/master/src/core/configuration.ts#L128 Use example

<dx-form>
  <dx-simple-item editorType="dxSelectBox" :editorOptions="{searchEnabled:true}">
     <my-data-source sourceName="name"></my-data-source>
</dx-simple-item>
</dx-form>

Steps to Reproduce

Current Behavior

Expected Behavior

Demo

Environment Details

• devextreme version: 18.1.7-pre-18291
• devextreme-vue version: 18.1.7-alpha.10
• vue version: 2.5.17

[lukyanovas]

I suppose, setting a template of Form Simple Item will be more simple and convenient in your case.

[genusP]

For setup data source need set 3 props (dataSource, displayExpr, valueExpr) in template and add code for extract data source from service.

This variant encapsulates all logic and linking the source is very simple.