Rename annotations

[berndruecker]

The annotations used in spring-zeebe will be renamed, according to our experiences using the library so far. We take the 8.1 release as a good moment in time to make that change.
All existing annotations will be deprecated, but keep working for now (and will be removed in a future release).

@ZeebeCustomHeaders --> @CustomHeaders
@ZeebeDeployment --> @Deployment, already deprecated field classPathResources will be removed in the new annotation
@ZeebeVariable --> @Variable
@ZeebeVariableAsType --> @VariableAsType
@ZeebeWorker --> @JobWorker, autoComplete default value will be switched from false to true (as we see auto completion as the default to be used in most cases). forceFetchAllVariables got renamed to fetchAllVariables.

See also #229 for some discussion on this issue

[berndruecker]

Todo: Adjust examples.

• https://github.com/camunda/camunda-platform-tutorials/blob/main/orchestrate-microservices/worker-java/src/main/java/io/camunda/getstarted/tutorial/Worker.java
• ...

[berndruecker]

@falko: Ping - it now exists on master and released as alpha1: https://github.com/camunda-community-hub/spring-zeebe/releases/tag/8.1.0-alpha1

[bulivlad]

maybe a nice to have here would be a new field in @ZeebeVariable to specify the name of the variable to be retrieved. This way the variable name in code would not be tied with the flow variable

[berndruecker]

We discussed this in the past - and so far we decided against it - as I don't see a good reason why the Java variable name has to be different than the process variable name. Actually, it might even easily add confusion. Technically, there would not be a big show stopper though - but as this is an easy addition with a sensible default, we can still ad this whenever we want (whereas we wanted to have the renaming part of the 8.1 release)