feat: Ability to lock to single conversation (#5881)

Adds the ability to lock conversation to a single thread for Whatsapp and Sms Inboxes when using outbound messages.

demo: https://www.loom.com/share/c9e1e563c8914837a4139dfdd2503fef

fixes: #4975

Co-authored-by: Nithin David <1277421+nithindavid@users.noreply.github.com>

app/javascript/dashboard/i18n/locale/en/inboxMgmt.json

@@ -388,6 +388,10 @@
         "ENABLED": "Enabled",
         "DISABLED": "Disabled"
       },
+      "LOCK_TO_SINGLE_CONVERSATION": {
+        "ENABLED": "Enabled",
+        "DISABLED": "Disabled"
+      },
       "ENABLE_HMAC": {
         "LABEL": "Enable"
       }
@@ -441,6 +445,8 @@
       "ENABLE_CSAT_SUB_TEXT": "Enable/Disable CSAT(Customer satisfaction) survey after resolving a conversation",
       "ENABLE_CONTINUITY_VIA_EMAIL": "Enable conversation continuity via email",
       "ENABLE_CONTINUITY_VIA_EMAIL_SUB_TEXT": "Conversations will continue over email if the contact email address is available.",
+      "LOCK_TO_SINGLE_CONVERSATION": "Lock to single conversation",
+      "LOCK_TO_SINGLE_CONVERSATION_SUB_TEXT": "Enable or disable multiple conversations for the same contact in this inbox",
       "INBOX_UPDATE_TITLE": "Inbox Settings",
       "INBOX_UPDATE_SUB_TEXT": "Update your inbox settings",
       "AUTO_ASSIGNMENT_SUB_TEXT": "Enable or disable the automatic assignment of new conversations to the agents added to this inbox.",