[WIP] Zero padding on MemTiles #6112

Job	Run time
ubuntu-22.04 llvm assert=ON rtti=ON	5m 25s
ubuntu-22.04 llvm assert=ON rtti=OFF	5m 27s
ubuntu-22.04 llvm assert=OFF rtti=ON	5m 8s
ubuntu-22.04 llvm assert=OFF rtti=OFF	5m 12s
ubuntu-22.04 gcc assert=ON rtti=ON	4m 59s
ubuntu-22.04 gcc assert=ON rtti=OFF	5m 2s
ubuntu-22.04 gcc assert=OFF rtti=ON	5m 17s
ubuntu-22.04 gcc assert=OFF rtti=OFF	5m 2s
ubuntu-24.04 llvm assert=ON rtti=ON	5m 15s
ubuntu-24.04 llvm assert=ON rtti=OFF	5m 25s
ubuntu-24.04 llvm assert=OFF rtti=ON	5m 5s
ubuntu-24.04 llvm assert=OFF rtti=OFF	5m 9s
ubuntu-24.04 gcc assert=ON rtti=ON	5m 14s
ubuntu-24.04 gcc assert=ON rtti=OFF	5m 1s
ubuntu-24.04 gcc assert=OFF rtti=ON	5m 17s
ubuntu-24.04 gcc assert=OFF rtti=OFF	5m 18s
ubuntu-20.04 gcc-11 assert=ON rtti=OFF	6m 32s
ubuntu-20.04 gcc-11 assert=OFF rtti=OFF	6m 12s
ubuntu-20.04 gcc-11 assert=ON rtti=ON	6m 20s
ubuntu-20.04 gcc-11 assert=OFF rtti=ON	7m 29s
windows-2019 msvc assert=ON rtti=ON	6m 51s
windows-2019 msvc assert=ON rtti=OFF	7m 33s
windows-2019 msvc assert=OFF rtti=ON	7m 33s
windows-2019 msvc assert=OFF rtti=OFF	7m 57s
	2h 19m 43s

Provide feedback