Limiting and controlling a write queue

__Proposal:__
According to the docs, WriteApi supports batching. If I understand correctly, there is something like an internal queue to send data to server in batches. An application is actively writes data, but I cannot control from my code if sending is fast enough and data are not infinitely collected in memory. It would be very useful to control the current size of the queue and set it's max size.

__Current behavior:__
Cannot find how to control and limit writing to DB server.

__Desired behavior:__
Be able to setup and control how data is written.

__Alternatives considered:__
Without the requested function, I have to implement my own queue and add new data by WriteApiAsync.

__Use case:__
Industrial monitoring systems generate a lot of data (we develop SCADA). And it's important to clearly understand if our service is able to send all data or not, and avoid using too much memory.
Thank you for your work.

No files, tests, or entry points are named in the issue; start by locating the C# WriteApi batching and queue implementation. Define how queue size limits and control should behave, including what happens when the limit is reached, then add coverage showing memory is bounded and writes remain observable.

Written by the indexing model from the issue text.