[Pitch] Add an Embedded File System to SwiftPM

Hi all, I would like to discuss adding a generated, read-only EmbeddedFileSystem to SwiftPM. It would let a target access resources declared with SwiftPM's existing Resource.embedInCode(_:) rule as a path-preserving file system. The intended use cases are self-contained command-line and server executables, WASI programs, test fixtures, templates, and static web content: cases where raw resources should travel with the linked program without requiring a Foundation bundle or a separately de...