Monitor is accessing the data only from ZeeQS

[aivinog1]

This is a part of #178. See this: https://github.com/zeebe-io/zeebe-simple-monitor/issues/178#issuecomment-724573831

So, needs to remove access to DB, exporters, and use only GraphQL API of ZeeQS.

[aivinog1]

@saig0 Hi! I have a question: if I understand correctly there is no prepared Java client for Zeeqs now? So what option suits better:

1. I will create a Java client lib in the ZeeQS project
2. I will generate it from ZeeQS's GraphQL files in this project (for example, grapqhl-java-codegen-maven-plugin)
3. I will use a Nodes client and create models myself

I actually prefer the first option (maybe someone will need it in the future), but what do you think?

[saig0]

The first option would be possible. But I don't know how generic this ZeeQS client would be. In GraphQL, you can specify the structure (i.e. the fields) of the response when sending the request. So, every consumer may send a different query. For the simple monitor, it is more an interim solution that the backend to a request to ZeeQS.

I recommend to make it easy and implement a basic client here that does exactly what you need. Like this one here: https://github.com/zeebe-io/bpmn-spec/blob/master/zeebe-test-runner/src/main/kotlin/io/zeebe/bpmnspec/runner/zeebe/zeeqs/ZeeqsClient.kt