[Opportunities] fix overlapping borders (#1091)

* [Opportunities] fix overlapping borders

* remove margin on SortAndFilterBar

* add margin-right to StyledBoard

front/src/modules/ui/board/components/BoardHeader.tsx

@@ -57,6 +57,7 @@ export function BoardHeader<SortField>({
 
   return (
     <TopBar
+      displayBottomBorder={false}
       leftComponent={
         <>
           <StyledIcon>{viewIcon}</StyledIcon>

front/src/modules/ui/board/components/StyledBoard.tsx

@@ -1,9 +1,10 @@
 import styled from '@emotion/styled';
 
 export const StyledBoard = styled.div`
-  border-radius: ${({ theme }) => theme.spacing(2)};
+  border-top: 1px solid ${({ theme }) => theme.border.color.light};
   display: flex;
   flex: 1;
   flex-direction: row;
-  padding-left: ${({ theme }) => theme.spacing(2)};
+  margin-left: ${({ theme }) => theme.spacing(2)};
+  margin-right: ${({ theme }) => theme.spacing(2)};
 `;