Client-only Micro/Macro Layout / Synthesis

[NiklasRentzCAU]

For the future, we want to allow to use KLighD technology while not needing to have a Java-based Server to improve performance and widen the use cases for KLighD. In a first step this includes using Langium as a DSL framework and use KLighD for such DSLs as well.

Current steps necessary for implementing the client-only workflow:
See here for some internal details.

• elkjs usable with KLighD-JS
• (together with step 1) micro layout on the client
• simple (Xtext/Langium) model to SKGraph synthesis on the client
  And to make writing more complex syntheses easier:
• helper code to write syntheses on the client

[NiklasRentzCAU]

Macro layout on the client is now possible. An issue related to that yet persists:

• macro layout only supports the layered algorithm
  calling elkjs with any other algorithm causes it to fail layout with a message like this one:
  Error: org.eclipse.elk.core.UnsupportedConfigurationException: Layout algorithm '"radial"' not found for Root Node file:///home/path-to-file/small.kgt > Node $root