Quick Info for <code> should not normalize whitespace

[sharwell]

This is a follow-up to #35667.

See #35667 (comment).

🔗 Also filed as AB#1322022

Sample code

/// <summary>
/// <code>
/// code line 1
/// code line 2
/// </code>
/// </summary>
private int value;

Expected result

Quick Info for value renders the summary code as a two-line code block with code font.

Actual result

Quick Info for value renders the summary code on one line with code font.