Improve behaviour of searching and adding contacts

- Styles are still supposed to be ugly
- Uniformize styles of list items for contacts and conversations
- Search field uses React Query for cache and get cleared properly
- Adding a contact updates the conversation list and closes the modal

Change-Id: I5949dff739a0f18fd39a89a744e1d26dcb36e2b2
diff --git a/client/src/components/Button.tsx b/client/src/components/Button.tsx
index 601f855..3ef3d94 100644
--- a/client/src/components/Button.tsx
+++ b/client/src/components/Button.tsx
@@ -351,7 +351,7 @@
   },
 }));
 
-const SquareButton = styled(({ Icon, ...props }: ShapedButtonProps) => (
+export const SquareButton = styled(({ Icon, ...props }: ShapedButtonProps) => (
   <IconButton {...props} disableRipple={true}>
     <Icon fontSize="inherit" />
   </IconButton>