Changes

[example] Update workflow example tests to handle differences between the java and node server implementation accordingly #22
- New assertions:
  - toContainClass - Checks if the element has the css class
  - toContainElement - Checks if the graph contains the element
  - toBeSelected - Checks that the element is selected
[example] Introduce/improve test cases for GLSP core functionality #23
Use playwright id selectors over plain # selectors #25

Potentially Breaking Changes

Combine get<ModelElement>BySelector and get<ModelElement>ByLocator methods #21
- e.g. getNodesBySelector/getNodesByLocator -> getNodes

Full Changelog: v2.2.1...v2.3.0