Issue with value remain same in internal constant of same blocks

[BkPankaj]

Summary:

In VisualCircuit, there is an issue: when there are multiple identical blocks, changing the internal constant value in one block affects all other identical blocks.

Steps to Reproduce:

1. Set up the VisualCircuit frontend and backend for setup refer this.
2. Run both frontend and backend.
3. Create a simple example containing same blocks (example CameraROS, LaserROS2,etc ) in the canvas.
4. Change the internal contant value of one block and notice that change in other same block.

Expected Behavior:

The change in internal constant value of the each block should not replicate in other same block.

Screenshots:

One block's internal constant value

Two same blocks in canvas

Other same type block internal constant value

[BkPankaj]

Issue resolved in #325 PR.