FIX: add support for pipelined and multi redis commands (#16682)

Latest redis interoduces a block form of multi / pipelined, this was incorrectly
passed through and not namespaced.

Fix also updates logster, we held off on upgrading it due to missing functions

lib/discourse_redis.rb

@@ -14,9 +14,9 @@ class DiscourseRedis
     GlobalSetting.redis_config
   end
 
-  def initialize(config = nil, namespace: true)
+  def initialize(config = nil, namespace: true, raw_redis: nil)
     @config = config || DiscourseRedis.config
-    @redis = DiscourseRedis.raw_connection(@config.dup)
+    @redis = raw_redis || DiscourseRedis.raw_connection(@config.dup)
     @namespace = namespace
   end
 
@@ -150,6 +150,26 @@ class DiscourseRedis
     Cache.new
   end
 
+  def multi
+    if block_given?
+      @redis.multi do |transaction|
+        yield DiscourseRedis.new(@config, namespace: @namespace, raw_redis: transaction)
+      end
+    else
+      @redis.multi
+    end
+  end
+
+  def pipelined
+    if block_given?
+      @redis.pipelined do |transaction|
+        yield DiscourseRedis.new(@config, namespace: @namespace, raw_redis: transaction)
+      end
+    else
+      @redis.pipelined
+    end
+  end
+
   private
 
   def remove_namespace(key)