layers: Eliminate statically allocated strings
layers: Eliminate statically allocated strings

See suspicious crashes when debug layers are enabled.
Believe this is due to memory overruns with fixed size
string allocations. This patch makes most of the allocations
compute the space needed to eliminate overruns and show
as much of the debug info as possible.
Also uses strncpy and strncat to ensure strings stay within
the limits of the buffer.

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools