common: refactor common library pt2 (#8588)

- remove common lib
- split settings, remove common-md
- move ipc interop/kb_layout to interop
- rename core -> settings, settings -> old_settings
- os-detect header-only; interop -> PowerToysInterop
- split notifications, move single-use headers where they're used
- winstore lib
- rename com utils
- rename Updating and Telemetry projects
- rename core -> settings-ui and remove examples folder
- rename settings-ui folder + consisent common/version include

src/settings-ui/Microsoft.PowerToys.Settings.UI/Styles/_Sizes.xaml

@@ -0,0 +1,19 @@
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:Microsoft.PowerToys.Settings.UI.Styles">
+
+    <x:Double x:Key="SidePanelWidth">240</x:Double>
+
+    <!-- Breakpoint for wide layout (side panel next to content) -->
+    <x:Double x:Key="WideLayoutMinWidth">720</x:Double>
+    
+    <!-- Breakpoint for small layout (side panel above content) -->
+    <x:Double x:Key="SmallLayoutMinWidth">600</x:Double>
+
+    <!-- Column spacing between content and sidepanel -->
+    <x:Double x:Key="DefaultColumnSpacing">24</x:Double>
+
+    <!-- Row spacing between content and sidepanel (in small mode) -->
+    <x:Double x:Key="DefaultRowSpacing">24</x:Double>
+</ResourceDictionary>