chore(data-widgets): rename data-widgets scss files to use partials

Author: rahmanunver

…gets/web/datagrid-design-properties.scss …ets/web/_datagrid-design-properties.scsspackages/modules/data-widgets/src/themesource/datawidgets/web/datagrid-design-properties.scss renamed to packages/modules/data-widgets/src/themesource/datawidgets/web/_datagrid-design-properties.scss packages/modules/data-widgets/src/themesource/datawidgets/web/datagrid-design-properties.scss renamed to packages/modules/data-widgets/src/themesource/datawidgets/web/_datagrid-design-properties.scss

@@ -4,7 +4,7 @@ $selected-color: #dadcde !default;
 $border-color: #ced0d3 !default;
 $arrow: "resources/dropdown-arrow.svg";
 
-@import "DatePicker";
+@import "date-picker";
 
 @font-face {
     font-family: "datagrid-filters";

…ce/datawidgets/web/datagrid-filters.scss …e/datawidgets/web/_datagrid-filters.scsspackages/modules/data-widgets/src/themesource/datawidgets/web/datagrid-filters.scss renamed to packages/modules/data-widgets/src/themesource/datawidgets/web/_datagrid-filters.scss packages/modules/data-widgets/src/themesource/datawidgets/web/datagrid-filters.scss renamed to packages/modules/data-widgets/src/themesource/datawidgets/web/_datagrid-filters.scss

@@ -1,6 +1,5 @@
 @import "../../../theme/web/custom-variables";
 @import "datagrid";
-@import "datagrid";
 @import "datagrid-filters";
 @import "datagrid-design-properties";
 @import "drop-down-sort";