core: simplify development settings

[dubisdev]

The goal of this PR is to simplify development settings so we can then migrate to webpack 5.

• Updated minor deps
• Removed webpack flags that were not being really used (color is activated by default if is supported by terminal)
• Simplify node_env settings by using webpack mode option.
• Removed -r @babel/register in webpack entries, as it is configured as a loader in the webpack.config files
• Removed auxiliar env variable HOT as it can be replaced by node_env