Custom status feature (#16835)

* Create the system console setting and send to webapp

* MI-1145: Add custom status APIs

* MI-1145 Add slash commands to set and clear status

* Add validation for custom status API

* Trim custom status message

* Code refactoring

- Run gofmt

- Rename constants

* Remove sendUserUpdated webhook event

* Fix recent custom status length

* Update error conditions

* Disable /status slash command when config setting is off

* MI-1155: Create the feature flag for custom status APIs and slash commands

* Move recent custom statuses to user preferences (#7)

* Move recent custom statuses to user preferences

* Code refactoring and feedback changes

* Update slash command text and emoji regex

* Make the custom status feature flag off by default

* Update SetCustomStatus, handle recents not set better

* Update status codes

* Update slash command handling

* Add telementry settings

* Fix i18n order

* Revert "Fix i18n order"

This reverts commit 499f7eaca8180336f5bcca360cc0133365899e08.

* Update i18n strings

i18n/en.json

@@ -715,6 +715,34 @@
     "id": "api.command_collapse.success",
     "translation": "Image links now collapse by default"
   },
+  {
+    "id": "api.command_custom_status.app_error",
+    "translation": "Error setting the status."
+  },
+  {
+    "id": "api.command_custom_status.clear.app_error",
+    "translation": "Error clearing the status."
+  },
+  {
+    "id": "api.command_custom_status.clear.success",
+    "translation": "Your status was cleared."
+  },
+  {
+    "id": "api.command_custom_status.desc",
+    "translation": "Set or clear your status"
+  },
+  {
+    "id": "api.command_custom_status.hint",
+    "translation": "[:emoji_name:] [status_message] or clear"
+  },
+  {
+    "id": "api.command_custom_status.name",
+    "translation": "status"
+  },
+  {
+    "id": "api.command_custom_status.success",
+    "translation": "Your status is set to “{{.EmojiName}} {{.StatusMessage}}”. You can change your status from the status popover in the channel sidebar header."
+  },
   {
     "id": "api.command_dnd.desc",
     "translation": "Do not disturb disables desktop and mobile push notifications."
@@ -1206,6 +1234,14 @@
     "id": "api.create_terms_of_service.empty_text.app_error",
     "translation": "Please enter text for your Custom Terms of Service."
   },
+  {
+    "id": "api.custom_status.disabled",
+    "translation": "Custom status feature has been disabled. Please contact your system administrator for details."
+  },
+  {
+    "id": "api.custom_status.recent_custom_statuses.delete.app_error",
+    "translation": "Failed to delete the recent status. Please try adding the status first or contact your system administrator for details."
+  },
   {
     "id": "api.email.send_warn_metric_ack.failure.app_error",
     "translation": "Failure to send admin acknowledgment email"