Feature - Extra metadata in constructed type and DBCDStorage

[KalopsiaTwilight]

This PR adds in three pieces of metadata for consumers of DBCD:

• Table and Column referenced by a reference field with a ForeignReferenceAttribute on the type's field.
• Size in bits allocated to a column in WDC formats via ColumnMeta with a SizeInBitsAttribute on type's field.
• The LayoutHash belonging to a DBCDStorage instance.

This is a metadata I am particularly interested for the WDBXEditor2 to be able to provide extra information in the editor and possibly limit the allowed size of integers for instance. I think these pieces of metadata could be generally useful to consumers of DBCD and fits in with the other metadata provided via Attributes atm.