MM-22051: Remove ToJson from model (part 1) (#18005)

https://mattermost.atlassian.net/browse/MM-22051

```release-note
Removed the following methods/functions:
(ad *AccessData) ToJson()
(ar *AccessResponse) ToJson()
(ar *AnalyticsRow) ToJson()
(ar AnalyticsRows) ToJson()
(o *Audit) ToJson()
(o Audits) ToJson()
(ad *AuthData) ToJson()
(ar *AuthorizeRequest) ToJson()
(o *ChannelPatch) ToJson()
(o *ChannelsWithCount) ToJson()
(o *ChannelCounts) ToJson()
(o *ChannelData) ToJson()
(o *ChannelMembers) ToJson()
(o *ChannelUnread) ToJson()
(o *ChannelUnreadAt) ToJson()
(o *ChannelStats) ToJson()
(o *ChannelView) ToJson()
(o *ChannelViewResponse) ToJson()
(o *ClusterDiscovery) ToJson()
(ci *ClusterInfo) ToJson()
(cs *ClusterStats) ToJson()
(o *Command) ToJson()
CommandListToJson(l []*Command) string
(o *CommandArgs) ToJson()
(cmr *CommandMoveRequest) ToJson()
(o *CommandResponse) ToJson()
(c *Compliance) ToJson()
(c Compliances) ToJson()
(o *Config) ToJson()
EmojiListToJson(emojiList []*Emoji)
```

plugin/helpers_config.go

@@ -4,6 +4,10 @@
 package plugin
 
 import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost-server/v6/model"
@@ -24,7 +28,17 @@ func (p *HelpersImpl) CheckRequiredServerConfiguration(req *model.Config) (bool,
 	}
 
 	mergedCfg := mc.(model.Config)
-	if mergedCfg.ToJson() != cfg.ToJson() {
+	cfgBuf, err := json.Marshal(cfg)
+	if err != nil {
+		return false, fmt.Errorf("failed to marshal config: %v", err)
+	}
+
+	mergedCfgBuf, err := json.Marshal(mergedCfg)
+	if err != nil {
+		return false, fmt.Errorf("failed to marshal merged config: %v", err)
+	}
+
+	if !bytes.Equal(cfgBuf, mergedCfgBuf) {
 		return false, nil
 	}