* Fixes#1856 Object Explorer needs Icons field for nodes separate from type/subtype
- Adds in the concept of a themeable icon path which matches VSCode's implementation. This should help support theme-based overrides in the future
- Fixes#1867 context menu should be extensible
- Added context keys to support "when" conditions on the new extensions
- Fixes issue where actions like New Query, scripting show up even if these are not valid for the provider type or object type
- Fixed node expansion bug where rapid connect / expand / disconnect could break the app (fix in ObjectExplorerService.onNodeExpanded)
- Major change to how internal actions work. These cannot assume the context has non-serializable objects. Opened up some APIs to make this easier to handle.
- Fixed a number of existing bugs in internal actions.
- Notably, DisconnectAction was adding a listener on each right-click on an active connection and never getting it disposed. This wasn't needed at all due to design changes.
- Another bug fix is that the Manage action now correctly navigates to the DB dashboard for database-level connections. Before this it went to the server-level dashboard.
* Define API for context info
