chore: update ReactFlow to v12

[lucaseduoli]

This pull request includes several updates to the frontend dependencies and various code refinements. The most important changes include the addition of a new package, updates to several component files to use this new package, and refactoring of state initialization and type definitions.

Dependency Updates:

• Added @xyflow/react version 12.3.6 to package.json and package-lock.json. [1] [2] [3]

Component Updates:

• Updated multiple components to use @xyflow/react instead of reactflow for various imports, such as BaseEdge, Position, useUpdateNodeInternals, and NodeResizer. [1] Fe00d011L1R1, [2] [3] [4]

State Initialization and Type Definitions:

• Refactored state initialization for description and display_name to use default empty strings. [1] [2]
• Made selected property optional in several components to improve type safety. [1] Fe00d011L1R1, [2] [3] F0519f22L15R15)

CSS Updates:

• Added a CSS rule to ensure .react-flow__controls-button svg elements have no fill.

Code Refactoring:

• Removed unused constants and imports to clean up the code.

These changes collectively improve the codebase by updating dependencies, enhancing type safety, and refining the overall structure.