This PR adds support for the new Vue-based GUI (aka `gui2`).
The user-facing changes are primarily:
* support for `./run gui2` and `./run ide2` commands (that build just the new GUI and the whole IDE package with new GUI embedded — respectively);
* the top-level `test` and `lint` commands will now invoke the relevant commands on the new GUI
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Co-authored-by: Paweł Grabarz <frizi09@gmail.com>
# Important Notes
- Binary LS endpoint is not yet handled.
- The parsing of provided source is not entirely correct, as each line (including imports) is treated as node. The usage of actual enso AST for nodes is not yet implemented.
- Modifications to the graph state are not yet synchronized back to the language server.
