Feat: View milvus configuration on GUI

[shanghaikid]

Describe the feature:
As a milvus user

• he can view milvus configuration and detailed explaination from GUI
• he can copy milvus configuration from GUI by one click, the copied content should be identical to milvus.yaml

Describe a specific use case for the feature:

• user may want to get milvus configuration file, other than connect to the cluster from CLI, it will be more convenient if the GUI provide a page to view it and copy it.

Ref: https://milvus.io/docs/v2.0.0/configuration_standalone-basic.md

[shanghaikid]

Milvus won't provide the API until 2.1, so we need to wait.