Consider splitting `google-chat-bot` module into several well-defined modules

[yuri-sergiichuk]

Why are we having only one module in this project? From the Java code I see client and server. Aren't they are modules?

Please arrange a project module for each Bounded Context.

Originally posted by @alexander-yevsyukov in #1

It is a good idea to split our single Gradle module into sub-modules with a well-defined separation. As mentioned, it may be a good idea to have separate modules for each Bounded Context, but we should consider talking it through and defining a correct policy for such modules separation in order to be able to reuse the same concept.