chore(breaking-changes): add upcoming article with breaking changes

Author: jivanova

upgrade/breaking-changes/3-0-0.md

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+---
+title: 3.0.0
+description: Handle the changes in the 3.0.0 release of the Telerik UI for Blazor components.
+page_title: Breaking Changes in 3.0.0
+slug: changes-in-3.0.0
+position: 1
+---
+
+# Upcoming Breaking Changes in 3.0.0
+
+> The 3.0.0 release will be shipped in mid January. The following list of breaking changes will be updated with detailed explanation how to migrate your project.
+
+## Component Changes
+
+- TileLayout - Introduce identifier of the TileLayout item. OnResize and OnReorder events will receive EventArgs that will point to the item that has been resized/reordered. This items comes from our [user voice](https://feedback.telerik.com/blazor/1489011)
+- TreeView - add `ExpandedItems` parameter to remove `ExpandedField`
+- Grid – change `OnRead` method to return the `Data`
+- Grid – use `IFilterDescriptor` in GridState instead of `FilterDescriptorBase`
+- DateInput – remove `ParsingErrorMessage` in favor of localization string for the error message
+- ContextMenu – add EventArgs to the OnClick event
+- All input elements – remove hardcoded width style in our Blazor components. In addition, the default style that comes from the themes will be updated to change the width to 100%.
+
+We are still designing changes in terms of editing by going through customer feedback. So, there might be changes coming from this direction as well.
+
+## Common Changes
+
+- `IconName` class will be removed. All icon names should be retrieved from documentation.
+- `ToODataString` extension method is moved to `Telerik.Blazor.Extensions` namespace.
+
+## Parameter Naming
+
+We have revised our code base and found several inconsistencies that need to be fixed in order to facilitate our customers where to look for similar 
+
+- `UpdateInterval` Parameter of Editor is changed to `DebounceDelay`
+- `Content` RenderFragment Parameter of the Drawer is changed to `DrawerContent`
+- `IsCanceled` Parameter in StepperStepChangeEventArgs is renamed to `IsCancelled`
+- `IsSeparatorField` is removed in favor of `SeparatorField`
+
+## Rendering & Themes
+
+- `k-widget` class is removed from the components
+- `width:100%` is the new default width of all components instead of `12.5em`
+- Html classes and dom elements hierarchy will be updated for Buttons, Inputs, Selects, DatePickers Checkbox, Switch. 
+- `k-state-focused` is renamed to `k-focus`