* Fix#4029 Ensure changeKernels always resolves, even in error states
This is necessary to unblock reverting the kernel on canceling Python install
- startSession now correctly sets up kernel information, since a kernel is loaded there.
- Remove call to change kernel on session initialize. This isn't needed due to refactor
- Handle kernel change failure by attempting to fall back to old kernel
- ExtensionHost $startNewSession now ensures errors are sent across the wire.
- Update AttachTo and Kernel dropdowns so they handle kernel being available. This is needed since other changes mean the session is likely ready before these get going
* Fix to handle python cancel and load existing scenarios
- Made changes to handle failure flow when Python dialog is canceled
- Made changes to handle initial load fail. Kernel and Attach To dropdowns show No Kernel / None and you can choose a kernel
- Added error wrapping in ext host so that string errors make it across and aren't lost.
* Fix#4356 New Notebook from connection doesn't connect
Fix new notebook error by passing profile instead of ID.
- I could've just sent the ID over, but this fix sets the stage for disconnected connections to work (since we have enough info to properly connect).
- There's a bug in NotebookModel blocking the disconnected connection part working, but Yurong's in progress fixes will unblock this. Hence checking in as-is and working to properly unblock once that's in.
* Support connection profile in commandline service
- Added new context API for things that want to work on commandline and object explorer
- Refactored commandlineservice slightly to be async & have a simpler execution flow (far fewer if/else statements)
* Fix unit tests
- Fixed 2 issues raised by tests (sholdn't do new query if no profile passed, shouldn't error on new query failing)
- Updated unit tests to pass as expected given changes to the APIs.
* Start single client session based on the default kernel or saved kernel in NB.
* Added kernel displayName to standardKernel.
Modified name to allign wtih Juptyer Kernel.name.
So we can show the displayName during startup and use the name to start the session.
* Change session.OnSessionReady event in KernelDropDown
* Added model.KernelChnaged for switching kernel in the same provider
* Fixed session.Ready sequence
* Fixed merge issues
* Solve merged issue
* Fixed wrong kernel name in saved NB
* Added new event in Model to notify kernel change.
Toolbar depends on ModelReady to load
* Change attachTo to wait for ModelReady like KenelDropDown
* sanitizeSavedKernelInfo to fix invalid kernel and display_name. For example: PySpark1111 and PySpark 1111
* Added _contextsChangingEmitter to change loadContext msg when changing kernel
* Resolve PR comments
- Jupyter completion item support was awaiting info before responding. Fix is to check if this is even a notebook cell first, then only await stuff if that's true
