🐛(react) fix calendar selects initialization and syncing

Select under the calendar component were not properly initialized,
leading to issues. Additionally, syncing the dropdowns with the calendar
state was causing unnecessary renders. Selects now update on user events
triggered by the toggle button, ensuring the selected item remains
up-to-date. The code has been refactored to eliminate duplication
and improve the component's readability and maintainability.

.changeset/strange-jeans-confess.md

@@ -0,0 +1,5 @@
+---
+"@openfun/cunningham-react": patch
+---
+
+Fix initial focused item on select opening under the calendar