MM-56876: Redis: first introduction (#27752)

```release-note
NONE
```

---------

Co-authored-by: Jesús Espino <jespinog@gmail.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/i18n/en.json

@@ -8530,6 +8530,10 @@
     "id": "model.config.is_valid.bleve_search.filename.app_error",
     "translation": "Bleve IndexingDir setting must be set when Bleve EnableIndexing is set to true"
   },
+  {
+    "id": "model.config.is_valid.cache_type.app_error",
+    "translation": "Cache type must be either lru or redis."
+  },
   {
     "id": "model.config.is_valid.cluster_email_batching.app_error",
     "translation": "Unable to enable email batching when clustering is enabled."
@@ -8642,6 +8646,10 @@
     "id": "model.config.is_valid.email_security.app_error",
     "translation": "Invalid connection security for email settings. Must be '', 'TLS', or 'STARTTLS'."
   },
+  {
+    "id": "model.config.is_valid.empty_redis_address.app_error",
+    "translation": "RedisAddress must be specified for redis cache type."
+  },
   {
     "id": "model.config.is_valid.encrypt_sql.app_error",
     "translation": "Invalid at rest encrypt key for SQL settings. Must be 32 chars or more."
@@ -8682,6 +8690,10 @@
     "id": "model.config.is_valid.import.retention_days_too_low.app_error",
     "translation": "Invalid value for RetentionDays. Value is too low."
   },
+  {
+    "id": "model.config.is_valid.invalid_redis_db.app_error",
+    "translation": "Redis DB must have a value greater or equal to zero."
+  },
   {
     "id": "model.config.is_valid.ldap_basedn",
     "translation": "AD/LDAP field \"BaseDN\" is required."