Dependencies security update

[maxwellred]

This is a security update for Fabric core.

Description of Changes

• Migrated from Gulp 3 to Gulp 4 + refactor of files to accommodate this change = changing a lot of 'gulp.task(...)' to exports and then composing them together with gulp.series() or gulp.parallel() .
• Removed incomplete Bundle functionality
• Changed gulp-cssnano dep to gulp-clean-css for minification since even the updated version of cssnano still has a security vulnerability
• Created custom plugins for csscomb (CssComb.js) and lintspaces (LintSpaces.js) and uninstallation of gulp-csscomb (tried updating gulp-csscomb but it still has sec vuln) and gulp-lintspaces (unmaintained repo)
• Removed now unused buildTasks and nukeTasks from BuildConfig.js
• Commented out a few couple of lines of css causing csscomb errors at build

[Jahnp]

Awesome, thank you for this, @maxwellred ! I'll take a closer look at this PR soon. Lot of great stuff here—excited to get it in.

[Jahnp]

Looks great, @maxwellred ! Thanks for all the hard work! I'm going to go ahead and merge this in.