Improve JSON->HTML conversion

The existing JSON to html conversion is quite unfortunate, as it runs
several very expensive regular expressions on an output to properly
invoke the correct behavior, and to escape things like links.  This
patchset adjusts the behavior to directly dump the tree to HTML,
skipping the json step entirely.

Most of the code was pulled from the nlohmann::serializer class.

Small side node:
This also resolves the CSP issue with the inline CSS classes that are
currently embedded in the json UI.

Note, in terms of user facing behavior, this finally fixes the CSS
issue, so the div is now centered as designed.  Previously it was left
justified.

Tested:
Ran several redfish schemas and compared to old ones.  Output appears
the same in the window, and content security policy warnings are gone.
Verified several links works as expected, and verified the behavior of
all base types, as well as empty arrays and empty objects.  All appear
to work correctly.

Signed-off-by: Ed Tanous <ed@tanous.net>
Change-Id: Id9bf6dc33acb1603f009de4cd322e81d83f334be