Feature/file bundling

[RChrHill]

• Adds a Serialization header that contains type-erased holders for Grid::GridSerializable objects
  • Main members: HadronsSerializable (type-erasure), HadronsSerializableGroup (collection of named HadronsSerializables)
• Creates Hadrons modules for generating groups of HadronsSerializables at runtime and writing them to disk
• Add file bundling support to MContraction::Meson and MContraction::WeakNonEye3pt
• Add a test demonstrating the use of the bundled result write on MContraction::Meson and MContraction::WeakNonEye3pt