Fix buttons and z-index (#1438)

* Fix buttons

* Remove useless code

front/src/modules/ui/table/components/EntityTable.tsx

@@ -43,7 +43,6 @@ const StyledTable = styled.table`
       border-right-color: transparent;
     }
     :last-of-type {
-      min-width: fit-content;
       width: 100%;
     }
   }
@@ -63,10 +62,6 @@ const StyledTable = styled.table`
       border-left-color: transparent;
       border-right-color: transparent;
     }
-    :last-of-type {
-      min-width: fit-content;
-      width: 100%;
-    }
   }
 `;
 

front/src/modules/ui/table/components/EntityTableHeader.tsx

@@ -198,8 +198,10 @@ export function EntityTableHeader() {
             <StyledAddIconButtonWrapper>
               <IconButton
                 size="medium"
+                variant="tertiary"
                 icon={<IconPlus />}
                 onClick={toggleColumnMenu}
+                position="middle"
               />
               {isColumnMenuOpen && (
                 <StyledEntityTableColumnMenu