Add copy paste and multiple section

[Hopson97]

No description provided.

[Copilot]

Pull Request Overview

This PR adds comprehensive copy-paste functionality and multi-object selection capabilities to the level editor, significantly improving the user workflow and efficiency.

• Implements multi-object selection with visual feedback and area selection tools
• Adds copy-paste functionality with CTRL+C/CTRL+V keyboard shortcuts and menu options
• Introduces 3D mouse picking for object selection in the 3D viewport
• Refactors GUI components to use a dedicated ImGuiExtras namespace

Reviewed Changes

Copilot reviewed 42 out of 42 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/Util/Util.h	Adds utility contains function for range checking
src/Util/ImGuiExtras.h/cpp	Moves ImGui helpers to dedicated namespace and adds enum selection widget
src/Screens/ScreenEditGame.h/cpp	Major refactor adding 3D picking, copy-paste handlers, and multi-object selection
src/Graphics/OpenGL/Texture.h	Adds R32I texture format for object picking
src/Graphics/Mesh.h/cpp	Adds level object mesh generation and color support
src/Editor/Tool.h/cpp	Implements area selection tool and refactors existing tools
src/Editor/EditorState.h/cpp	Introduces Selection struct for managing multiple selected objects
src/Editor/EditorLevel.h/cpp	Adds bulk operations and 3D picking support
src/Editor/EditorEventHandlers.h/cpp	New handlers for object movement and copy-paste operations
src/Editor/Actions.h/cpp	Adds bulk actions for multi-object operations
Various object files	Updates 2D rendering to support selection offset visualization

Comments suppressed due to low confidence (1)

src/Editor/Tool.cpp:496

• Typo in comment: 'corrsponding' should be 'corresponding'

        selection_cube_start_ = cube_start;