feat(NewBlockLayer, ConnectionLayer): added validation and duplication of blocks by a group

[Antamansid]

Brief Summary of PR

Key Changes

Connection Validation

• Added isConnectionAllowed function to ConnectionLayer that validates if a connection can be created from a source component
• Updated event documentation with more detailed information about connection events and how they can be prevented

Block Duplication Validation

• Added isDuplicateAllowed function to NewBlockLayer that validates if a block can be duplicated
• Implemented validation logic that checks each block before duplication and cancels the process if no blocks can be duplicated

Group Block Duplication

• Added support for duplicating multiple blocks at once when a selected block is Alt+dragged
• Implemented two duplication modes:
  1. "Single block duplication": When Alt+dragging a non-selected block, only that block is duplicated
  2. "Multiple block duplication": When Alt+dragging a selected block, all selected blocks are duplicated together
• Updated event types to handle multiple blocks instead of a single block
• Added code to maintain the relative positions of blocks during group duplication

Technical Improvements

• Added AbortController integration for ConnectionLayer and NewBlockLayer for proper handling of operation cancellations
• Updated documentation to reflect the new functionality
• Fixed a bug with addLayer that was causing unnecessary graph re-renders

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