feat(utils): replace slick-core extend utils with node-extend

the `extend` function that was added to SlickGrid core utils seems to be causing problems when Angular-Slickgrid are published on external website as per this issue: ghiscoding/Angular-Slickgrid#1334
- the node-extend came from this popular npm package: https://github.com/justmoon/node-extend/blob/v1.2.0/test/index.js
the reason, I reimplemented it in here is because the npm package is using old CJS syntax and is not ESM friendly, moving the code in here would be better with newer syntax and less CJS code, also less external dependencies