refactor(button-group): update styles and simplify layout structure across all samples - #4020

refactor(button-group): update styles and simplify layout structure across all samples#4020

desig9stein wants to merge 3 commits into

vnextIgniteUI/igniteui-angular-samples:vnextfrom

mpopov/update-samples-stylesIgniteUI/igniteui-angular-samples:mpopov/update-samples-stylesCopy head branch name to clipboard