[Doc] Update encryption and decryption documentation for cpp, python and nodejs clients

[tuteng]

What issue do you find in Pulsar docs?

https://pulsar.apache.org/docs/en/security-encryption/#get-started
The cpp, python and nodejs clients do not support the ecdsa algorithm and we should consider highlighting it in the documentation

What is your suggestion?

https://pulsar.apache.org/docs/en/security-encryption/#get-started
The cpp, python and nodejs clients do not support the ecdsa algorithm and we should consider highlighting it in the documentation

Do you have any references?

https://github.com/apache/pulsar/blob/master/pulsar-client-cpp/lib/MessageCrypto.cc
No ecdsa algorithm related content found

Would you like to fix this issue?

The cpp, python and nodejs clients do not support the ecdsa algorithm and we should consider highlighting it in the documentation

Note

• I have researched my question.

[Anonymitaet]

@momo-jun can you take a look at this issue? Thanks

[momo-jun]

Hi @tuteng , this issue has been addressed in #15526 . Can you pls review that PR? Thanks.