cmake: Build with debugging information by default

Unless -DCMAKE_BUILD_TYPE is passed, always build with debugging
information turned on. Debugging information will go into its own
artifact anyway.
build: All targets depend on runtime components

Add runtime components to devel and all additional targets.
ostbuild-qemu-pull-deploy: Quiet boot

Suppress kernel messages during boot.
ostbuild-qemu-pull-deploy: Disk image size to 2 GiB

Increase disk image size so that devel tree can fit into it.