Change from tuple to struct for storing metadata of stored collections

[tmadlener]

Currently we use a std::tuple to store some metatdata related to collections:

podio/include/podio/utilities/RootHelpers.h

Lines 18 to 21 in 5afdefd

	// A collection of additional information that describes the collection: the
	// collectionID, the collection (data) type, whether it is a subset
	// collection, and its schema version
	using CollectionWriteInfoT = std::tuple<uint32_t, std::string, bool, unsigned int>;

This makes it hard to read via julia and also from a maintainability point of view it would be nicer, if this was something like

struct CollectionWriteInfo {
  uint32_t collectionID;
  std::string dataType;
  bool isSubset;
  unsigned int schemaVersion;
};

@peremato I suppose something along these lines should work?

[peremato]

What about adding also the collection name? In this case you need only one branch for all information.

[tmadlener]

Yeah, I could add that. I have to check how we can deduplicate some parts, because that information is also stored via the CollectionIDTable.