fix(typography): replace font-size numbers with mixins (#UIM-271)

packages/mosaic-dev/card/styles.scss

@@ -14,10 +14,6 @@ mc-card {
     flex-direction: row;
 }
 
-.mc-upload-to-cloud_24 {
-    font-size: 32px;
-}
-
 .simple-content {
     padding: 8px;
 }

packages/mosaic/datepicker/_datepicker-theme.scss

@@ -6,7 +6,6 @@
 $mc-datepicker-selected-today-box-shadow-width: 1px;
 $mc-datepicker-selected-fade-amount: 0.6;
 $mc-datepicker-today-fade-amount: 0.2;
-$mc-calendar-weekday-table-font-size: 11px !default;
 
 @mixin _mc-datepicker-color($color) {
     .mc-calendar__body_selected {
@@ -152,7 +151,7 @@ $mc-calendar-weekday-table-font-size: 11px !default;
 
     .mc-calendar__table-header th {
         font: {
-            size: $mc-calendar-weekday-table-font-size;
+            size: mc-font-size($config, caption);
             weight: mc-font-weight($config, body);
         }
     }

packages/mosaic/popover/popover.scss

@@ -57,7 +57,6 @@ $mc-popover-large-width: 640px;
 }
 
 .mc-popover__container {
-    font-size: 15px;
     border-radius: $border-radius-base;
     border-width: $border-size;
     border-style: solid;