Refactor Overworld Editor and enhance settings management for v3 features

- Removed the outdated ZEML layout file and associated references to streamline the OverworldEditor.
- Introduced the OverworldEditorManager class to encapsulate v3 settings management, improving code organization and maintainability.
- Updated the OverworldEditor to utilize ImGui for layout, enhancing user interaction and flexibility.
- Enhanced the changelog with detailed descriptions of new features and improvements, including a comprehensive undo/redo system and advanced palette management.
- Removed deprecated diagnostic patterns from the clangd configuration to improve code quality checks.

assets/layouts/overworld.zeml

@@ -1,25 +0,0 @@
-BeginTabBar title="##OwEditorTabBar" {
-  BeginTabItem title="Map Editor" {
-    Function id="owToolset",
-
-    Table id="##owEditTable" count="2" flags="Resizable|Reorderable|Hideable|BordersOuter|BordersV" {
-      TableSetupColumn title="Canvas" flags="WidthStretch",
-      TableSetupColumn title="Tile Selector" flags="WidthFixed" width="256",
-      TableHeadersRow
-      TableNextRow,
-      TableNextColumn,
-      Function id="OverworldCanvas",
-      TableNextColumn,
-      Function id="OverworldTileSelector",
-    }
-  }
-  BeginTabItem title="Tile16 Editor" {
-    Function id="OwTile16Editor"
-  }
-  BeginTabItem title "Graphics Group Editor" {
-    Function id="OwGfxGroupEditor"
-  }
-  BeginTabItem title="Usage Statistics" {
-    Function id="OwUsageStats"
-  }
-}