[DOC]Domain Model - Message transmission model Optimization

Document Optimization:
Message Transmission Model Introduction The introduction to the consumer model is not very clear and complete, and it may be ambiguous to read.

Regarding the original description of point-to-point, I personally feel that this mode is more like a shared messaging pattern. If we change it to the following, readers may find it easier to understand without ambiguity.
After the overall modification, the consumer model can be divided into the following three categories:
- Point-to-Point [The newly added mode is the point-to-point model]
- Publish-Subscribe [Using the previous publish-subscribe model]
- Shared [The previous point-to-point aligns better with this pattern]

Locate the Domain Model documentation and read the current consumer-model introduction and message-mode descriptions. Revise the explanation to distinguish Point-to-Point, Publish-Subscribe, and Shared models without ambiguity, then verify that the surrounding text and diagrams use the same terminology.

Written by the indexing model from the issue text.