Markdown renderer unescape is not totally fixed

Issue Type: Bug

I found this existing issue about Markdown renderer escapes, which was supposed to be fixed, but found an edge case that is still broken.

Load this repro in Code, then mouse over the "value" property name in data.jsonc. You will see that the link ends with a superfluous literal backslash character, and clicking it opens a URL that ends with %5C.

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VS Code version: Code 1.62.2 (3a6960b964327f0e3882ce18fcebd07ed191b316, 2021-11-11T20:56:38.428Z) OS version: Windows_NT x64 10.0.19043 Restricted Mode: No

Item	Value
CPUs	Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz (8 x 2112)
GPU Status	2d_canvas: enabledgpu_compositing: enabledmultiple_raster_threads: enabled_onoop_rasterization: enabledopengl: enabled_onrasterization: enabledskia_renderer: enabled_onvideo_decode: enabledvulkan: disabled_offwebgl: enabledwebgl2: enabled
Load (avg)	undefined
Memory (System)	15.92GB (2.87GB free)
Process Argv	--crash-reporter-id 104bab69-2434-4424-a670-b65cf70439b5
Screen Reader	no
VM	0%

Extension	Author (truncated)	Version
vscode-m3u	af4	1.0.0
ng-template	Ang	13.0.0
npm-intellisense	chr	1.4.0
vscode-svgviewer	css	2.0.0
vscode-markdownlint	Dav	0.45.0
githistory	don	0.6.19
xml	Dot	2.5.1
EditorConfig	Edi	0.16.4
vscode-npm-script	eg2	0.3.23
json-tools	eri	1.0.2
JasmineSnippets	jor	0.1.0
xml-format	mik	1.1.2
remote-ssh	ms-	0.66.1
remote-ssh-edit	ms-	0.66.1
powershell	ms-	2021.10.2
java	red	1.0.0
vscode-autohotkey	sle	0.2.2
vscode-hexdump	sle	1.8.1
vscodeintellicode	Vis	1.2.14
html-css-class-completion	Zig	1.20.0