Unify the blockquote parsing logic for messages and rawInput

[Skalakid]

This PR changes and unifies the blockquote parsing logic for the NewDot messages and the Live Markdown Input. Currently, the parsing result is different when the shouldKeepRawInput variable is true. Thanks to the changes in this PR, the results are consistent (visually). The only difference is that the tags are being grouped when shouldKeepRawInput=false.

Example:

> test
>> test
> test

NewDot sent message shouldKeepRawInput=false

<blockquote>test<br /><blockquote>test</blockquote>test</blockquote>

Live Markdown Input shouldKeepRawInput=true

<blockquote> test</blockquote>
<blockquote><blockquote> test</blockquote></blockquote>
<blockquote> test</blockquote>

Fixed Issues

$ Expensify/App#45154
$ Expensify/App#47951

Tests

1. Applying changes to both the NewDot app and the Live Markdown Input
2. Verify if the markdown is the same when writing the message and after sending it

QA

Same as Tests

[Pujan92]

commenting for the assignment.