Various style fixes (#13534)

* Various style fixes

- Fix the rest of the monochrome borders for arc-green
- Fix close icon position on system notice modal and padding
- Fix selectable table color for arc-green

* proper fix for close icon

Co-authored-by: Lauris BH <lauris@nix.lv>

web_src/less/_user.less

@@ -29,7 +29,7 @@
             list-style: none;
 
             &:not(:last-child) {
-              border-bottom: 1px solid #eaeaea;
+              border-bottom: 1px solid var(--color-secondary);
             }
 
             .svg,