Unify the namespaceId init way in nacosConfigService and nacosNamingService

[horizonzy]

Describe the bug
In nacoConfigService, if user didn't set namespace in properties, it will use "" as default value.
In nacosNamingService, if user didn't set namespace in properites, it will use public str as default value.

Maybe we should unify the init way of namespace. make nacosConfigService to be same as naconsNamingService

[horizonzy]

in #4262, If we use public:*:* to replace ':*:*', when user didn't config namespace in properties, in naming module, it can work well, because the namespace will be set public. but in config module, it will cause problem, the namespace set as "". the permission can't pass.

[KomachiSion]

Move to #3525