chore(npm): cleanup dependencies, move to Dart Sass

UI/WebServerResources/scss/components/button/button.scss

@@ -1,6 +1,10 @@
 /// button.scss -*- Mode: scss; indent-tabs-mode: nil; basic-offset: 2 -*-
 @import 'extends';
 
+md-button {
+  font-weight: 600;
+}
+
 md-sidenav md-list .md-button {
   font-weight: normal;
 }
@@ -150,7 +154,7 @@ $button-fab-height: 56px;
 a.md-button.sg-icon-button,
 .md-button.sg-icon-button,
 md-list md-list-item button.md-button.sg-icon-button {
-  @extend .md-button.md-icon-button;
+  @extend .md-button, .md-icon-button;
   //transition: $iconButton-transition;
   min-width: $iconButton-size;
   &:hover:not([disabled]),

UI/WebServerResources/scss/components/timepicker/timepicker.scss

@@ -185,7 +185,7 @@ sg-timepicker {
 }
 
 .sg-timepicker-triangle-button.md-button.md-icon-button {
-  @extend .md-datepicker-triangle-button.md-button.md-icon-button;
+  @extend .md-datepicker-triangle-button, .md-button, .md-icon-button;
 }
 
 // Disabled state for all elements of the picker.

UI/WebServerResources/scss/core/typography.scss

@@ -147,7 +147,7 @@ $sg-typo-scale: (
     45,
     56,
     112
-) !global;
+);
 
 // todo: fix that
 //@function sg-font-sizes($size-List: $sg-typo-scale, $prefix: '$sg-font-size') {