Form inputs in inline mode are surrounded by a <pre> element

There's a comment in XWikiDocument.display:

// If the Syntax id is not "xwiki/1.0", i.e. if the new rendering engine is used then we need to
// protect the content with a <pre> since otherwise whitespaces will be stripped by the HTML macro
// used to surround the object property content (see below).

But this comment is wrong, the html macro doesn't collapse whitespaces inside <input> and <textarea> elements.

The <pre> element causes problems, since its styles must be manually overridden to revert back to non-pre behavior. Related: XWIKI-4652 and XE-824.