Makes GUI text construction 30x faster for empty strings, otherwise less
than 1% faster.
Split the constructor into smaller helper functions to reduce nesting
and improve readability.
Change m_GeneratedTexts from pointer to reference, so that one doesn't
have to keep track to delete it correctly in several places, without
having to resort to copy or move assignments but constructing in place.
Mark CGUIText as NONCOPYABLE and MOVABLE which is already implicitly the
case due to the CGUISpriteInstance members, refs 0a7d0ecdde/D2133,
D2163/3028551b91.
Differential Revision: https://code.wildfiregames.com/D2168
Prepared by the GUIText.h file split in 838889ab12 / D2167.
Comments By: Vladislav
Tested on: gcc 9, clang 8, VS2015, Jenkins
Inlining tested using: clang -Rpass=inline and gcc -Winline
This was SVN commit r22679.
