[BUG] Extra parsing of lane elements which are not in the BPMN spec

[csouchet]

Describe the bug
Currently, in bpmn-visualization@0.26.0, we parse the Lane from a LaneSet and from a Process directly. (See the ProcessConverter https://github.com/process-analytics/bpmn-visualization-js/blob/v0.26.0/src/component/parser/json/converter/ProcessConverter.ts#L95)
However according to the BPMN specification, Lane lane is defined only within a LaneSet.

So, the Lanes are not parsed correctly.

To Reproduce
Steps to reproduce the behavior:

1. Load a bpmn file with a wrong format (lane directly in process and no laneset)
2. See no error and the lane is display

Expected behavior
The lane should be not displayed, and we should have a warning/error for the bad format.

Desktop (please complete the following information):

• Version 0.25.3, 0.26.0

Additional context
If we remove the bad parsing, there is:

• 7 tests failed in BpmnJsonParser.lane.test.ts
• no error in the integration tests
• no error in the e2e tests

BPMN Specification

When a `Lane` is defined it is contained within a `LaneSet`, which is contained within a `Process`.

ℹ️ For more information: https://www.omg.org/spec/BPMN/2.0.2/PDF

⚠️ Check the contribution guidelines for BPMN support

[tbouffard]

I have checked the reference files in the bpmn-miwg-test-suite repository.
All the files that have lanes declare laneset > lane, never declare lanes directly.

If this is in the BPMN specification, this is what it was expected. With this is verification, this is for sure. 🤟🏿