resourceloader: Move style deprecation warnings to <body>
Follows-up If35a106c7. These log messages are not criticial and
should not be in the <head> competing with stylesheets and article
content. Move them to the end of <body> instead, nearby other
low-priority script tags.
The getBodyHtml() method from ClientHtml was empty, but has been
non-empty in the past. It's fine to repopulate.
Also, while ClientHtml::getBodyHtml was empty, there are additional
RLQ scripts created by OutputPage that do exist even without this.
Namely, there is a <script> for wgPageParseReport, and one for
wgBackendResponseTime etc.
Change-Id: Ibda7091bdcd5ed207395b20196cdc33df926a24c