Fix JSDoc types for services

[nikku]

What should we do?

Our existing JSDoc type definitions on services are built in a way that makes it impossible for IDEs to use. Related to https://github.com/bpmn-io/diagram-js/issues/501 we should correct type definitions on services defined within bpmn-js.

Fixing these types by pointing to the actual implementations allows us to TypeScript type hinting to find potential miss-use:

Related, but not necessarily similar we should fix type definitions on service APIs (https://github.com/bpmn-io/bpmn-js/issues/1378).

Related, and likely required, we should integrate type linting tsc --pretty into the build.

Why should we do it?

This improves the editing experience for new contributors, allows for jump to definition on public APIs and so on.

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Child of https://github.com/bpmn-io/bpmn-js/issues/1002