Store the export manifest in ModPack to allow mulitple mod packs to have
different data exported. This is necessary as the export contains the
settings prototypes needed to create a proper UI for mod settings.
For now the useLocale and useItemMetadata interfaces uses the manifest
for a default mod pack set in the master config.
The Factorio Mod Portal uses and provides SHA1 hashes of mods, so it
makes sense to align the ModPack and ModInfo structures to sha1 by
renaming the genericly named hash property to sha1.
Add ModPack data type with corresponding storage on the master, messages
to create, update and delete them, as well as commands to invoke them.
The ModPack data type contains a list of mods with versions and optional
sha1 hashes, and mod settings to be used.
Hornwitser