Add localization and UI updates for receiver actions

Added new localized strings for "Recently used recipients" and
"Skip" in German, English, and French resource files. Updated
the `CreateEnvelopeWizardPopup.razor` to enhance the "Add
Receiver" button with a primary render style and a new CSS
class. Introduced styles for the button in `sender-page.css`
to improve its appearance with a minimum width, bold font,
and box shadow.

EnvelopeGenerator.Application/Resources/Resource.de-DE.resx

@@ -567,6 +567,12 @@
   <data name="AddReceiver" xml:space="preserve">
     <value>Empfänger hinzufügen</value>
   </data>
+  <data name="SenderWizard_RecentReceivers" xml:space="preserve">
+    <value>Zuletzt verwendete Empfänger</value>
+  </data>
+  <data name="Skip" xml:space="preserve">
+    <value>Überspringen</value>
+  </data>
   <data name="DeleteReceiver" xml:space="preserve">
     <value>Empfänger löschen</value>
   </data>

EnvelopeGenerator.Application/Resources/Resource.en-US.resx

@@ -567,6 +567,12 @@
   <data name="AddReceiver" xml:space="preserve">
     <value>Add Receiver</value>
   </data>
+  <data name="SenderWizard_RecentReceivers" xml:space="preserve">
+    <value>Recently used recipients</value>
+  </data>
+  <data name="Skip" xml:space="preserve">
+    <value>Skip</value>
+  </data>
   <data name="DeleteReceiver" xml:space="preserve">
     <value>Delete Receiver</value>
   </data>

EnvelopeGenerator.Application/Resources/Resource.fr-FR.resx

@@ -567,6 +567,12 @@
   <data name="AddReceiver" xml:space="preserve">
     <value>Ajouter un destinataire</value>
   </data>
+  <data name="SenderWizard_RecentReceivers" xml:space="preserve">
+    <value>Destinataires recents</value>
+  </data>
+  <data name="Skip" xml:space="preserve">
+    <value>Passer</value>
+  </data>
   <data name="DeleteReceiver" xml:space="preserve">
     <value>Supprimer le destinataire</value>
   </data>