Fix duplicated IDs issue while using multiple modals in a single page (#82)

* Fix Modal title hardcoded id

Title: Fix duplicated IDs issue while using multiple modals in a single page

Description: This pull request addresses the issue of duplicated IDs by modifying the code to use the modal ID for creating the H1 ID. This change ensures that the H1 ID remains unique, even when multiple modals are present on the same page. 

Signed-off-by: Clément Lelong <clement@numericite.eu>

* Update src/Modal.tsx

Co-authored-by: Joseph Garrone <joseph.garrone.gj@gmail.com>
Signed-off-by: Clément Lelong <clement@numericite.eu>

* Update src/Modal.tsx

Co-authored-by: Joseph Garrone <joseph.garrone.gj@gmail.com>
Signed-off-by: Clément Lelong <clement@numericite.eu>

* Update src/Modal.tsx

Co-authored-by: Joseph Garrone <joseph.garrone.gj@gmail.com>
Signed-off-by: Clément Lelong <clement@numericite.eu>

* Update src/Modal.tsx

Signed-off-by: Joseph Garrone <joseph.garrone.gj@gmail.com>

---------

Signed-off-by: Clément Lelong <clement@numericite.eu>
Signed-off-by: Joseph Garrone <joseph.garrone.gj@gmail.com>
Co-authored-by: Joseph Garrone <joseph.garrone.gj@gmail.com>

Author: ClementNumericite

src/Modal.tsx

@@ -59,10 +59,10 @@ const Modal = memo(
                 : [buttons_props];
 
         const { t } = useTranslation();
-
+        const titleId= `fr-modal-title-${id}`;
         return (
             <dialog
-                aria-labelledby="fr-modal-title-modal-1"
+                aria-labelledby={titleId}
                 role="dialog"
                 id={id}
                 className={cx(fr.cx("fr-modal", topAnchor && "fr-modal--top"), className)}
@@ -96,7 +96,7 @@ const Modal = memo(
                                 </div>
                                 <div className={fr.cx("fr-modal__content")}>
                                     <h1
-                                        id="fr-modal-title-modal-1"
+                                        id={titleId}
                                         className={fr.cx("fr-modal__title")}
                                     >
                                         {iconId !== undefined && (