feat: Add inbox details endpoint (#5549)

This change targets the public API and is related to the Inbox with channel type API.
Exposes public inbox details under /public/api/v1/inboxes/{inbox_identifier}. This allows access to feature flags and business hours configured for the inbox.

ref: #5514

swagger/paths/index.yml

@@ -70,6 +70,14 @@
 
 # ------------  Public API routes  ------------#
 
+# Inbox
+
+/public/api/v1/inboxes/{inbox_identifier}:
+  parameters:
+    - $ref: '#/parameters/public_inbox_identifier'
+  get:
+    $ref: './public/inboxes/show.yml'
+
 # Contacts
 
 /public/api/v1/inboxes/{inbox_identifier}/contacts:

swagger/paths/public/inboxes/show.yml

@@ -0,0 +1,15 @@
+tags:
+  - Inbox API
+operationId: get-details-of-a-inbox
+summary: Inbox details
+description: Get the details of an inbox
+security: []
+responses:
+  200:
+    description: Success
+    schema:
+      $ref: '#/definitions/public_inbox'
+  401:
+    description: Unauthorized
+  404:
+    description: The given inbox does not exist