[aider assisted] MM-61888: Add ClientSideUserIds field to MetricsSettings (#30127)

We add a new config setting to allow the admin to set a fixed
list of userIDs to track for all client side webapp metrics.

This gives the admin to get a deeper look at how the application
is behaving for a single user.

A new section in the system console is also added for the user
to edit this setting from the UI.

https://mattermost.atlassian.net/browse/MM-61888

```release-note
A new config setting MetricsSettings.ClientSideUserIds is added
where you can set the user ids you want to track for client side webapp
metrics.
```

* fix lint errors

```release-note
NONE
```

* fixing tests

```release-note
NONE
```

server/public/model/incoming_webhook.go

@@ -66,7 +66,7 @@ type IncomingWebhooksWithCount struct {
 
 func (o *IncomingWebhook) IsValid() *AppError {
 	if !IsValidId(o.Id) {
-		return NewAppError("IncomingWebhook.IsValid", "model.incoming_hook.id.app_error", nil, "", http.StatusBadRequest)
+		return NewAppError("IncomingWebhook.IsValid", "model.incoming_hook.id.app_error", map[string]any{"Id": o.Id}, "", http.StatusBadRequest)
 	}
 
 	if o.CreateAt == 0 {