Use ArrayPool in ArrayBuilder<T> (#11830)

...ents/Blazor/Build/test/RuntimeDependenciesResolverTest.cs

...nts/ref/Microsoft.AspNetCore.Components.netstandard2.0.cs

src/Components/Components/src/RenderTree/ArrayBuilder.cs

...mponents/Components/src/RenderTree/ArrayBuilderSegment.cs

...Components/Components/src/RenderTree/RenderTreeBuilder.cs

src/Components/Components/src/Rendering/ComponentState.cs

...Components/Components/src/Rendering/RenderBatchBuilder.cs

src/Components/Components/src/Rendering/Renderer.cs

src/Components/Components/src/Routing/Router.cs

src/Components/Components/test/RenderTreeDiffBuilderTest.cs

...ents/Components/test/Rendering/ArrayBuilderSegmentTest.cs

src/Components/Components/test/Rendering/ArrayBuilderTest.cs

src/Components/Components/test/Rendering/TestArrayPool.cs