Add license declare for Nacos and its dependencies

[caqhy]

Fixes #ISSUSE_ID.

Changes proposed in this pull request:

• Add license declare for Nacos and its dependencies

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• My code follows the code of conduct of this project.
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• I have made corresponding changes to the documentation.
• I have added corresponding unit tests for my changes.

[caqhy]

#20984

[linghengqian]

• Just wanted to confirm, use Nacos Client 1.x instead of Nacos Client 2.x, is this because [Q] Nacos client 1.x policy and 2.x package mode alibaba/nacos#9091 is not closed yet?

[caqhy]

• Just wanted to confirm, use Nacos Client 1.x instead of Nacos Client 2.x, is this because [Q] Nacos client 1.x policy and 2.x package mode alibaba/nacos#9091 is not closed yet?

The reason for using nacos-client1. x instead of nacos-client2. x is registerInstance 注册覆盖前面的实例，不能注册多实例 #5863
At present, shardingsphere cluster mode repository nacos module uses NamingService, which is unreasonable. In the future, it needs to be switched to ConfigService. However, the configuration center features of nacos cannot fully implement ClusterPersistRepository. I have raised expectations to the nacos community.What features do you expect from Nacos 3.0? #9129