Tools: add predicates to comply with WP9

[mrwunderbar666]

WP9 created a set of meta variables that all inventories should contain. Update the data structure to account for these changes.

• open_source: bool
• defunct: bool
• license: single choice (look up list of software licenses)
• user_access: single choice (e.g., free, registration, upon request, pay)

linked_opted_materials as defined by WP9 should be links to other entries such as papers and scientific publications

[mrwunderbar666]

Also add predicates for concept variables as discussed within WP3