Refactor the binary import and dependency resolution infrastructure to
support multiple platforms (Linux, Windows, macOS) via a
configuration-driven root system.
Major changes:
* Overhaul PDB and DWARF importers for platform-aware debug info
loading.
* Refactor LDDTree into a template-based architecture with
platform-specific implementations (ELF, PE/COFF).
* Mostly rewrite the PDB importer, which had significant limitations.
Fix the behavior of binary importers by propagating the path of the
input binary from revng2 downwards, allowing finding `.debug` files in
the correct paths.
This is a big step to split revng-lift in two parts: one that only
writes the model and one that actually lifts to LLVM IR.
* Introduce `revng import binary`
* Split off `BinaryFile.h`
* Drop `revng.h`
* `GeneratedCodeBasicInfo`: use model
* Reduce role of `GeneratedCodeBasicInfo` in favor of
`model::Architecture` and `model::Register` methods
* `CodeGenerator`: adopt `RawBinaryView` and model
* `JumpTargetManager`: adopt `RawBinaryView` and model
* `ExternalJumpsHandler`: adopt model
* `InstructionTranslator`: discard `Architecture` in favor of
`EndianessMismatch`
* Many other changes