Notebook: move cell command recreates cells instead of reuse

[rebornix]

Issue Type: Bug

• Move cell in notebook
• The moved cell is now recreated in the ext host side other than just moving its position.

VS Code version: Code - Insiders 1.45.0-insider (d342048, 2020-04-23T07:46:52.128Z)
OS version: Darwin x64 19.2.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz (16 x 2400)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	3, 3, 2
Memory (System)	32.00GB (0.17GB free)
Process Argv	-psn_0_16011076
Screen Reader	no
VM	0%

Extensions (21)

Extension	Author (truncated)	Version
comment-tagged-templates	bie	0.3.0
github-markdown-preview	bie	0.0.2
markdown-emoji	bie	0.0.9
markdown-preview-github-styles	bie	0.1.6
gitlens	eam	10.2.1
tsl-problem-matcher	eam	0.1.1
vscode-pull-request-github-insiders	Git	2020.4.32581
vscode-docker	ms-	1.1.0
vscode-language-pack-zh-hans	MS-	1.45.0
remote-containers	ms-	0.112.0
remote-ssh-edit-nightly	ms-	2020.4.9540
remote-ssh-nightly	ms-	2020.4.9540
js-debug-nightly	ms-	2020.4.1517
powershell	ms-	2020.4.0
vscode-github-issue-notebooks	ms-	0.0.10
vsliveshare	ms-	1.0.2048
debugger-for-chrome	msj	4.12.6
kuskus-extensions-pack	ros	1.0.1
kuskus-kusto-language-server	ros	1.0.1
kuskus-kusto-syntax-highlighting	ros	1.1.8
sourcekit-lsp	unp	0.0.1

(4 theme extensions excluded)