Upgrade node-sass version or replace it

[gitcommitshow]

Currently node-sass compatibility with node versions is complex.
The current node-sass version (v4) is not supported for stable node versions higher than v14. Which limits the supported node version of this projects. We can do one of the two things

A. Upgrade the node-sass version to v6 or v7 so we can have more node stable versions supported (i.e. from node v8 upto node v16)
B. As node-sass is deprecated, replace it with its alternate but active libraries