fix(table): set height of mat-header-row to 56px (#8215)

Author: Gabriel

src/lib/table/table.scss

@@ -1,16 +1,24 @@
+$mat-header-row-height: 56px;
 $mat-row-height: 48px;
 $mat-row-horizontal-padding: 24px;
 
 .mat-table {
   display: block;
 }
 
+.mat-header-row {
+  min-height: $mat-header-row-height;
+}
+
+.mat-row {
+  min-height: $mat-row-height;
+}
+
 .mat-row, .mat-header-row {
   display: flex;
   border-bottom-width: 1px;
   border-bottom-style: solid;
   align-items: center;
-  min-height: $mat-row-height;
   padding: 0 $mat-row-horizontal-padding;
 }