💄(react) use overflow auto instead of scroll

Currently, Tooltip and Datagrid components are set to always scroll bar.
This is weird, as the scrollbar is always shown even if this is not
needed. Instead, we use `auto` value to display it only when
it is needed

.changeset/hip-masks-love.md

@@ -0,0 +1,5 @@
+---
+"@openfun/cunningham-react": patch
+---
+
+Use `overflow:auto` instead of `overflow:scroll`