PLT-5308 Caching layer part 2 (#6973)

* Adding Reaction store cache layer example

* Implementing reaction store in new caching system.

* Redis for reaction store

* Adding redis library

* Adding invalidation for DeleteAllWithEmojiName and other minor enhancements

vendor/github.com/go-redis/redis/export_test.go

@@ -0,0 +1,35 @@
+package redis
+
+import (
+	"net"
+	"time"
+
+	"github.com/go-redis/redis/internal/pool"
+)
+
+func (c *baseClient) Pool() pool.Pooler {
+	return c.connPool
+}
+
+func (c *PubSub) SetNetConn(netConn net.Conn) {
+	c.cn = pool.NewConn(netConn)
+}
+
+func (c *PubSub) ReceiveMessageTimeout(timeout time.Duration) (*Message, error) {
+	return c.receiveMessage(timeout)
+}
+
+func (c *ClusterClient) SlotAddrs(slot int) []string {
+	var addrs []string
+	for _, n := range c.state().slotNodes(slot) {
+		addrs = append(addrs, n.Client.getAddr())
+	}
+	return addrs
+}
+
+// SwapSlot swaps a slot's master/slave address for testing MOVED redirects.
+func (c *ClusterClient) SwapSlotNodes(slot int) []string {
+	nodes := c.state().slots[slot]
+	nodes[0], nodes[1] = nodes[1], nodes[0]
+	return c.SlotAddrs(slot)
+}