armbian-next: artifacts: firmware/rootfs and actual usage of artifacts during image build

- artifacts: introduce `ARTIFACT_IGNORE_CACHE=yes`
- artifacts: introduce `DONT_BUILD_ARTIFACTS`, list of artifacts that if not found cached, fail the build
- kernel_package_source() is no more
- a long dissertation about kernels, families, and the universe
- artifacts: actually use rootfs artifact for image build
- artifacts: detangle via artifact_base_dir
- artifacts: rootfs: use folders in artifact_name; include cache_type
- artifacts: some cleanups / validations
- rootfs artifact; drop old rootfs cli
- artifacts: new CLI shortcuts; remove old firmware CLI
- artifacts: full firmware & usage
- use firmware artifacts in image build and install its debs
- kernel artifact sans legacy; use tmpdir for .deb target for all packages
- legacy artifact versions is no more; pack/unpack now in common obtain;
- artifacts: uboot: cleanup legacy renaming, use artifact version directly
- artifacts: add firmware (small) artifact
- deploy uboot to loop from artifact; allow tty to artifact; todos for cleaning
- fixes, kernel dtb/headers conditional; remove `.git` from Makefile url; use mapfile for finding files to hash
  - completely remove KERNEL_HAS_WORKING_HEADERS_FULL_SOURCE and `kernel_package_callback_linux_headers_full_source()`
  - don't use realpath for artifact_file_relative
  - curb some warnings
  - fix: only install headers & dtbs if such exist
- kernel .config hook modification hash versioning
- OCI_TARGET_BASE vs per-artifact defaults; only deploy to remote from CLI with OTB
- artifact revolver & installing into image
  - add artifact_map_packages and artifact_map_debs dicts
  - revolver accumulates all info
  - REPOSITORY_INSTALL is no more (for uboot/kernel, later others)
  - rename `VER` to `IMAGE_INSTALLED_KERNEL_VERSION`

extensions/flash-kernel.sh

@@ -15,7 +15,7 @@ function extension_prepare_config__prepare_flash_kernel() {
 	export BOOTSIZE=0                                                           # No separate /boot, flash-kernel will "flash" the kernel+initrd to the firmware part.
 	export UEFI_MOUNT_POINT="/boot/firmware"                                    # mount uefi partition at /boot/firmware
 	export CLOUD_INIT_CONFIG_LOCATION="/boot/firmware"                          # use /boot/firmware for cloud-init as well
-	export VER="${FK__PUBLISHED_KERNEL_VERSION}"                                # For the VERSION
+	export IMAGE_INSTALLED_KERNEL_VERSION="${FK__PUBLISHED_KERNEL_VERSION}"                                # For the VERSION
 	export EXTRA_BSP_NAME="${EXTRA_BSP_NAME}-fk${FK__PUBLISHED_KERNEL_VERSION}" # Unique bsp name.
 }