Recursive serialization with UUIDs

[ariasanovsky]

Tag all serialized intermedaites with UUIDs to avoid race conditions during macro expansion and compilation.

• [x] _Field
• [x] _Union
• [x] _Map
• [x] _Spindle (new struct formed from compatabile collections of _Union and _Map)
• I used Db{} for the naming convention in spindle_db
• [ ] DevSpindle, HostSpindnle -> DevBuffer, HostBuffer