Move glyph cache manager into font-client-plugin-cache-handler

Move glyph cache manager into font-client-plugin-cache-handler

Currently, glyph cache manager owned by each font-face-cache-item.
That mean, we can hold glyph cache as
{The number of font type} x {The number of font size} x 128(default).

This patch make we hold GlyphCacheManager hold as singletone.
So we can cache the glyph maximum 128(default) not relative with
the number of font type & size.

Change-Id: I85e3cec3d160a57496e839f0b87a24655861f981
Signed-off-by: Eunki, Hong <eunkiki.hong@samsung.com>