Full plumb through of Session support. Also fixed some test issues
- Load session and get necessary information in kernels list
- Run Cell button now works as expected
- Added a ToggleAction base class which can be used for anything that switches icons. I'd still prefer to have this be dynamic and as clean as the extension classes
- Fixed account test unhandled promise rejections (caused by incorrect / invalid tests) that made it hard to see all the test run output.
Implements provider contribution in the MainThreadNotebook, with matching function calls in the ExtHostNotebook class. This will allow us to proxy through notebook providers (specifically, creation of a notebook manager with required content, server managers) from an extension up through to the main process.
Implemented in this PR:
- Callthroughs for content and server manager APIs
- Very basic unit tests covering provider & manager registration
Not implemented:
- Fuller unit tests on the specific callthrough methods for content & server manager.
- Contribution point needed to test this (so we can actually pass through the extension's existing Notebook implementation)
