Outline view and completions for Enso code in VSCode.
# Important Notes
This PR provides the necessary infrastructure for building VSCode extension that includes `enso_parser` library compiled for all supported platforms.
VSCode extension can now use libraries from `sbt` that are `publishM2`-ready. To make that possible a documentation must have been provided and fixed for those modules - hence so many changes in `.scala` classes.
<img width="862" alt="image" src="https://github.com/enso-org/enso/assets/26887752/7374bf41-bdc6-4322-b562-85a2e761de2a">
Last, but not least. The outline view and completions display something.
Let's _untie_ the [VSCode Enso extension](https://marketplace.visualstudio.com/items?itemName=Enso.enso4vscode) from `sbt` commands. Let's **open any Enso file in the editor** and then use _F5_ or _Ctrl-F5_ to execute it. Let the user choose which `bin/enso` script to use for execution completely skipping the need for `sbt`.
Recently a classpath misconfiguration appeared in `engine/runtime` project:
The problem was caused by the `XyzTest.java` files being incorrectly assigned to `engine/runtime/src/main/java` source root and its classpath (which obviously doesn't contain JUnit). This PR restricts the `srcCp` to `inputDir`, when it is known. That properly assignes the `XyzTest.java` files to `engine/runtime/src/test/java` source root. The IGV as well as VSCode support seems to recognize unit test classpath properly now.
Fixing node.js dependencies as:
```bash
enso/tools/enso4igv$ mvn clean install -Pvsix
```
was broken. Making sure the VSIX build is part of the _actions workflow_.
# Important Notes
To reproduce/verify remove `enso/tools/enso4igv/node_modules` first and try to build.
This PR adds sources for Enso language support in IGV (and NetBeans). The support is based on TextMate grammar shown in the editor and registration of the Enso language so IGV can find it. Then this PR adds new GitHub Actions workflow file to build the project using Maven.
