Fix: component value label on canvas doesn't update after editing

[ImranFarhat01]

Problem

Component value label on the canvas did not update after using SET
PARAMETERS in the Component Properties panel.

Root Cause

The Redux state was updated correctly, but nothing told mxGraph to
refresh the displayed cell label. The canvas label is built from
per-component-type rules (plain value for resistors/inductors/
capacitors, no value line for transistors/MOSFETs, an extra
expression appended with a space, etc), and that logic only existed
inside the netlist generation function, never wired up to the
Properties panel.

Fix

• Extracted the label-building rules into a single shared function,
  buildComponentCanvasLabel(baseName, properties)
• Netlist generation now calls this function once instead of
  repeating the same label-building line across 7 different branches
• The Properties panel now looks up the edited cell directly via the
  graph model, preserves the component's base name, rebuilds the
  value portion using the shared function, and applies it
  immediately to the canvas

Testing

• Resistor: edited value, canvas immediately shows the component name
  and new value together, name preserved
• Capacitor: same, name preserved
• Voltage source with a custom waveform expression: edited value,
  canvas immediately shows the name and new expression together
• Generated a netlist after these edits to confirm the underlying
  simulation output is unaffected by the refactor