Support for type parameters.

[david9991]

The tplant does not support type parameters. Therefore, when the following code was used:

class NodeDependenciesProvider implements vscode.TreeDataProvider<Dependency> {
...

The PlantUML output did not include the type information behind the implements keyword:

@startuml
class NodeDependenciesProvider implements  {
    +getTreeItem(element: Dependency): vscode.TreeItem
    +getChildren(element?: Dependency | undefined): Thenable<Dependency[]>
}
...
@enduml

And in preview window I got this error