quote reply doesn't handle nested replies

[diminutivesloop]

Issue Type: Bug

Steps to Reproduce:

1. Click the "Quote Reply" button for a PR comment that quote-replies to another comment.
2. Click the "Comment" button.

Result:
The original comment is nested inside two quote boxes, while the previous quote-reply text is unquoted.

Extension version: 0.31.1
VS Code version: Code 1.61.2 (Universal) (6cba118ac49a1b88332f312a8f67186f7f3c1643, 2021-10-19T15:49:28.381Z)
OS version: Darwin x64 20.6.0
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2600)
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	3, 3, 3
Memory (System)	32.00GB (0.16GB free)
Process Argv	--crash-reporter-id ed50f89e-497f-43cd-86f3-a73119f730ed
Screen Reader	no
VM	0%

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pygetstartedt3:30385195
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[alexr00]

@burkeholland this could be another good one for you!