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/internal/errors.go

@@ -0,0 +1,75 @@
+package internal
+
+import (
+	"io"
+	"net"
+	"strings"
+)
+
+const Nil = RedisError("redis: nil")
+
+type RedisError string
+
+func (e RedisError) Error() string { return string(e) }
+
+func IsRetryableError(err error) bool {
+	return IsNetworkError(err) || err.Error() == "ERR max number of clients reached"
+}
+
+func IsInternalError(err error) bool {
+	_, ok := err.(RedisError)
+	return ok
+}
+
+func IsNetworkError(err error) bool {
+	if err == io.EOF {
+		return true
+	}
+	_, ok := err.(net.Error)
+	return ok
+}
+
+func IsBadConn(err error, allowTimeout bool) bool {
+	if err == nil {
+		return false
+	}
+	if IsInternalError(err) {
+		return false
+	}
+	if allowTimeout {
+		if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
+			return false
+		}
+	}
+	return true
+}
+
+func IsMovedError(err error) (moved bool, ask bool, addr string) {
+	if !IsInternalError(err) {
+		return
+	}
+
+	s := err.Error()
+	if strings.HasPrefix(s, "MOVED ") {
+		moved = true
+	} else if strings.HasPrefix(s, "ASK ") {
+		ask = true
+	} else {
+		return
+	}
+
+	ind := strings.LastIndex(s, " ")
+	if ind == -1 {
+		return false, false, ""
+	}
+	addr = s[ind+1:]
+	return
+}
+
+func IsLoadingError(err error) bool {
+	return strings.HasPrefix(err.Error(), "LOADING")
+}
+
+func IsExecAbortError(err error) bool {
+	return strings.HasPrefix(err.Error(), "EXECABORT")
+}