Fix: add setMaterialMap utility to safely switch Texture to VideoTexture #31934

[mahi656]

Description:
This PR introduces a new utility setMaterialMap.js that addresses issue #31934.

• The setMaterialMap function is designed to be called whenever assigning a texture to a material's map property, particularly for special cases like VideoTexture, where material.needsUpdate must be set to ensure proper rendering updates.

Changes:

• Added utils/setMaterialMap.js as a reusable function to safely assign textures to materials.
• Ensures material.needsUpdate = true automatically when switching from a regular Texture to a VideoTexture (or any dynamic texture), preventing potential rendering issues or crashes.

Usage Example:
Instead of manually doing:

material.map = videoTexture;
material.needsUpdate = true;

[Mugen87]

This helper is not ideal since it performs operations which are not always required when setting a map. If you just want to exchange an existing texture there is no need to set needsUpdate to true.

three.js is designed in a way that needsUpdate should be used on app level.