[cosmosdb] Rename CosmosClient methods

[xirzec]

There was feedback to rename top-level methods on CosmosClient with read instead of get, but that doesn't really make sense for the methods getWriteEndpoint and getReadEndpoint. It's also not clear how/where these are used.

[github-actions]

Hi @xirzec, we deeply appreciate your input into this project. Regrettably, this issue has remained inactive for over 2 years, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.