Fixes

Incorporating minor C++ runtime rendering fixes.

• More cleanups for Vulkan bootstrapping 54f8301
• Reduce the # of arguments required for Vulkan context creation 95b2979
• More Build Options 69f120c
• define rive::math::pi to be the same as m_pi b43936c
• Split up subpass from resource allocation for draw. Move draw limit check to before resource allocation occurs (and can fail) d97fd2d
• Vulkan - Atlas texture barrier fix 731ed90