More Label touchups (margins) (#10722)

* labels with onClick don't need .pointer. No labels need `m-r-5`

* making Timer a proper Label

* a little linting

* addresing (helpful, thanks) comment

superset-frontend/src/explore/components/ExploreChartHeader.jsx

@@ -72,8 +72,9 @@ const StyledHeader = styled.div`
     align-items: center;
     justify-content: flex-end;
 
-    .btn-group {
+    > .btn-group {
       flex: 0 0 auto;
+      margin-left: ${({ theme }) => theme.gridUnit}px;
     }
   }
 `;

superset-frontend/src/explore/components/RowCountLabel.jsx

@@ -47,7 +47,7 @@ export default function RowCountLabel({ rowcount, limit, suffix }) {
   );
   return (
     <TooltipWrapper label="tt-rowcount" tooltip={tooltip}>
-      <Label bsStyle={bsStyle} className="m-r-5 pointer">
+      <Label bsStyle={bsStyle}>
         {formattedRowCount} {suffix}
       </Label>
     </TooltipWrapper>

superset-frontend/src/explore/components/controls/FixedOrMetricControl.jsx

@@ -104,7 +104,7 @@ export default class FixedOrMetricControl extends React.Component {
     return (
       <div>
         <ControlHeader {...this.props} />
-        <Label className="pointer" onClick={this.toggle}>
+        <Label onClick={this.toggle}>
           {this.state.type === controlTypes.fixed && (
             <span>{this.state.fixedValue}</span>
           )}