Support more config namespaces

[24kpure]

What is the purpose of the change

With the increasingly complex business and the increasing number of microservices, the configuration of services relying on a single namespace can't meet the requirements. Maybe we should support more config namespaces, just like other configuration centers（apollo，nacos）

Brief changelog

• support more config namespaces
• remove useless code in org.springframework.cloud.zookeeper.config.ZookeeperPropertySourceLocator

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[24kpure]

@spencergibb Eager for your advice.

[24kpure]

@msievers @ryanjbaxter help~

[24kpure]

@marcingrzejszczak help~ Eager for your advice.

[24kpure]

@msievers @ryanjbaxter help~

[spencergibb]

The earliest this would be available is November with 4.1.0, so we'll look at it sometime between now and then.

[24kpure]

The earliest this would be available is November with 4.1.0, so we'll look at it sometime between now and then.

Thanks for your response. I have raised another pr #312 about config load.Btw,I'd like to ask for your advice that local cache file is ok when zk can't not be connected.

[24kpure]

The earliest this would be available is November with 4.1.0, so we'll look at it sometime between now and then.

@spencergibb please,give me some advice about this commit.

[24kpure]

I have raised this pr for 8 months,but no one took part in conversation. I am sharing my idea of the project, where are members?
@spencergibb @msievers @ryanjbaxter

[24kpure]

@spencergibb @msievers @ryanjbaxter

[24kpure]

The earliest this would be available is November with 4.1.0, so we'll look at it sometime between now and then.

I have raised this pr for a year, Can you have a look.