NoteEditor: Stop replacing newlines with "<br>"

[david-allison]

Review Goals

• Determine if there are any cases where we want to perform this operation (checksum, duplicates)?

Purpose / Description

To my knowledge, Anki Desktop does not do this, and it causes various bugs

Fixes

Fixes #4189
Fixes #3304

Approach

Remove the offending code

How Has This Been Tested?

• Ran Unit Tests
• After editing a card, html column has been changed #4189 no longer occurs.

Checklist

• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code

[david-allison]

Okay... back to the drawing board. We need an end-to-end test to ensure that newlines are replaced in the CardViewer.

aa
bb
gg

is now rendered as aa bb gg

[david-allison]

I don't think this is going to get resolved before the Visual Editor comes along. Let's not clutter up the PRs