MM-33903 rename slash commands & permission (#17494)

- rename slash commands
    - "remote" -> "secure-connection"
    - "share" -> "share-channel"
- change status icons to text (translated)
- remove channel invite "Description" field
- rename permission "manage_remote_clusters" -> "manage_secure_connections"

model/migration.go

@@ -24,7 +24,7 @@ const (
 	MIGRATION_KEY_ADD_SYSTEM_ROLES_PERMISSIONS                = "add_system_roles_permissions"
 	MIGRATION_KEY_ADD_BILLING_PERMISSIONS                     = "add_billing_permissions"
 	MIGRATION_KEY_ADD_MANAGE_SHARED_CHANNEL_PERMISSIONS       = "manage_shared_channel_permissions"
-	MIGRATION_KEY_ADD_MANAGE_REMOTE_CLUSTERS_PERMISSIONS      = "manage_remote_clusters_permissions"
+	MIGRATION_KEY_ADD_MANAGE_SECURE_CONNECTIONS_PERMISSIONS   = "manage_secure_connections_permissions"
 	MIGRATION_KEY_ADD_DOWNLOAD_COMPLIANCE_EXPORT_RESULTS      = "download_compliance_export_results"
 	MIGRATION_KEY_ADD_COMPLIANCE_SUBSECTION_PERMISSIONS       = "compliance_subsection_permissions"
 	MIGRATION_KEY_ADD_EXPERIMENTAL_SUBSECTION_PERMISSIONS     = "experimental_subsection_permissions"