Grids: Fix columns[].headerFilter.groupInterval Placeholders

[arman-boyakhchyan]

No description provided.

[Copilot]

Pull request overview

This PR updates the documentation for the columns[].headerFilter.groupInterval option by adjusting the shared Common Types page and adding component-specific API reference pages for DataGrid and TreeList.

Changes:

• Updated ColumnHeaderFilter.groupInterval examples to use DataGrid-specific component names in several snippets.
• Added new API reference pages for dxDataGrid.Options.columns.headerFilter.groupInterval and dxTreeList.Options.columns.headerFilter.groupInterval.
• Adjusted some framework-specific code snippets (jQuery/Angular/Vue/React) around groupInterval: null + calculateFilterExpression.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
api-reference/40 Common Types/15 grids/ColumnHeaderFilter/groupInterval.md	Updates examples for groupInterval; currently mixes DataGrid-specific code with placeholder-based snippets.
api-reference/10 UI Components/dxTreeList/1 Configuration/columns/headerFilter/groupInterval.md	New TreeList API page for groupInterval; currently includes DataGrid-specific demo/link references.
api-reference/10 UI Components/dxDataGrid/1 Configuration/columns/headerFilter/groupInterval.md	New DataGrid API page for groupInterval.

Comments suppressed due to low confidence (3)

api-reference/40 Common Types/15 grids/ColumnHeaderFilter/groupInterval.md:88

• The Angular module import was changed to DxDataGridModule, but this Common Types page still uses {WidgetName}/{widget-name} placeholders elsewhere. Keeping this file generic (placeholders) avoids mixing hard-coded DataGrid API with templated snippets.

    import { DxDataGridModule } from 'devextreme-angular';

    @NgModule({
        declarations: [
            AppComponent

api-reference/40 Common Types/15 grids/ColumnHeaderFilter/groupInterval.md:107

• The Vue example hard-codes but still imports from 'devextreme-vue/{widget-name}'. This mix of hard-coded component names with placeholders makes the snippet invalid as written. Keep the example placeholder-based (or update both tags and import path consistently).

        <DxDataGrid ... >
            <DxColumn ...
                data-type="date"
                :calculate-filter-expression="calculateFilterExpression">
                <DxHeaderFilter

api-reference/40 Common Types/15 grids/ColumnHeaderFilter/groupInterval.md:139

• The React example now uses the DataGrid component but still imports from 'devextreme-react/{widget-name}'. This mismatch makes the snippet invalid as written. Keep the example placeholder-based (or update both component name and import path consistently).

    import { DataGrid, Column, HeaderFilter } from 'devextreme-react/{widget-name}';

    function calculateFilterExpression (value, operation, target) {
        if(value && target === "headerFilter") {
            return [this.dataField, operation, value];