0030663: Visualization - synthesize italic style for a font having no italic style...

0030663: Visualization - synthesize italic style for a font having no italic style [backport OCCT720]

Font_FTFont now defines shear transformation to synthesize italic style for fonts having no such style.
Font_FontMgr::FindFont() and command "vfont -find" have been extended with -strict option
to check whether the given font is actually registered or not.
Font_FTFont::Init() - added constructor from memory buffer.
Second Font_FTFont::Init() override has been renamed to Font_FTFont::FindAndInit()
to avoid ambiguity between two similar methods taking full font path and font name as string.

# Conflicts:
#	src/AIS/AIS_Dimension.cxx
#	src/OpenGl/OpenGl_Text.cxx