add: first version for load command and workspace filtering

[lethalSopaper]

Overview

This PR implements the core layout restoration functionality (load command) and the functionality of workspace filtering for both save and load operations.

Features

Layout Restoration (load command)

• Direct restoration approach: Applications are launched sequentially into target workspaces with Sway's automatic tiling handling positioning
• Container hierarchy reconstruction: Supports split containers (horizontal/vertical), tabbed containers, and stacked containers
• Synchronization delays: Brief pauses between operations, this ensures proper window initialization
• Restoration reporting: Detailed results including workspaces restored, applications launched/failed, and error list
• Workspace focus preservation: Returns to originally focused workspace after restoration

Workspace Filtering (--skip-workspace flag)

• Skip specific workspaces during save/load operations
• Flexible identifier formats:
  • By number: --skip-workspace=1,2,3
  • By name: --skip-workspace=mail,dev,AUDIO
  • Mixed: --skip-workspace=1,dev,3
• Shell quoting support: Workspace names with spaces require quotes: --skip-workspace="my workspace"
• Validation: Pre-flight checks reject non-existent workspaces with clear error messages

Enhanced Flag System

• Proper flag handling: --help / -h and --version / -v now work as real flags (not commands)
• Flexible positioning: Flags can appear before or after commands

Testing

No testing file are implemented yet for this base functionality