change(columns): moved some css values to variables for cleaner custo…

…mizations

- this way in a theme package you can create theme/addons/volto-addons/columnsBlocks/columns.variables and use other values in order
 to get the desired css values to be compiled

src/less/columns.less

@@ -185,15 +185,15 @@
 
   .ui.grid > .column-blocks-wrapper,
   .ui.grid > .column-blocks-wrapper:not(.row) {
-    padding-top: 0.5em;
-    padding-bottom: 0.5em;
+    padding-top: @columnBlocksWrapperPaddingTop;
+    padding-bottom: @columnBlocksWrapperPaddingBottom;
   }
 }
 
 .ui.grid.column-grid {
   padding: @columnGridPadding;
-  margin-top: 0.8rem;
-  margin-bottom: 0.8rem;
+  margin-top: @columnGridMarginTop;
+  margin-bottom: @columnGridMarginBottom;
 }
 /* remove padding from column-grid when we have styled-with-bg style from volto-block-style */
 .styled-with-bg .grid.column-grid {

src/less/columns.variables

@@ -1 +1,9 @@
-@columnGridPadding: 0;
+@columnGridPadding: 0;
+
+// Column block wrapper
+@columnBlocksWrapperPaddingTop: 0.5em;
+@columnBlocksWrapperPaddingBottom: 0.5em;
+
+// Column grid
+@columnGridMarginTop: 0.8rem;
+@columnGridMarginBottom: 0.8rem;