v0.6.0

• bumped rascal to 0.28.0 for the addition of vis::Graphs and fixes in util::Sampling and vis::Charts.
• fixed issues with the IDEServices::edit function, in the VS Code terminal context and VS Code parameterized DSL LSP server context, with logical locations and locations with line/column information (both previously unsupported), for use in interactive visualizations (for example).
• allow VS Code extensions to use rascal-vscode independently of installed rascal; this means DSL implementations can run their own native extension when they are finished being developed.
• as a result, rascal-vscode is now also an independent npm package.