[structure view] show details of types as sub-nodes

[martinlippert]

Some type nodes in the structure tree could reveal additional information as sub-nodes, e.g.:

• repositories: show the query methods
• configuration properties: show the individual properties
• controllers: show the request mappins

Those details are already available from the outline view as specific hierarchical Spring document symbols. The goal here is to display those additional nodes as sub-nodes of the type nodes in the structure view.

[martinlippert]

You can enable this experimental feature via -Denable-structure-view-details when running the language server.