Improvement of the EMF metamodel and model languages

[tsaglam]

This PR addresses multiple issues with the three EMF language modules, thus improving the modeling plagiarism detection with JPlag. Relates to #576.

This PR includes:

• Fix subtree reordering normalization for the EMF model language
• Fix the metamodel parsing for EMF model language
• Improve the generic textual syntax for EMF (meta)models (GenericEmfTreeView)'
• Updates to the EMF language module readmes
• Enables the use of the --normalize flag for the model tree normalization, thus effectively disabling it per default.

The last point references an overhaul of the textual syntax. It now parses any EMF-based model and attempts to derive a textual view from the available information, including names, types, features, values, and so on. This might look good for some models, but not for others. In an ideal world, each metamodel has a dedicated language model with a metamodel-specific visualization. However, as a fallback, this simple textual view should be fine.

Previously, it looked like this:

BookStore
  Book
  Book

Now, it looks like this:

BookStore #0: owner="David Brown", location="Street 12, Top Town, ...", books=["Parry Hotter and the Hallow Deathly", "Harry Potter and the Deathly Hallows"]
  Book #0: name="Parry Hotter and the...", isbn="175112"
  Book #1: name="Harry Potter and the...", isbn="157221"

[uuqjz]

Most of my issues stem from EMF

[sonarqubecloud]

Quality Gate passed for 'JPlag Plagiarism Detector'

Issues
0 New issues

Measures
0 Security Hotspots
93.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud