Societies are being treated the same way as committees

One-sentence description

• Change voorzitter/chairman to contactpersoon/contact person.
• Either remove being in a society from 'achievements for Thalia', or rename 'achievements for Thalia' to 'history' or something alike.
• In case the latter option is chosen, please also fix the following: being in a society is already visible under 'achievements for Thalia', even when the society is not active, and thus hidden, yet.

Why?

• Societies don't have a voorzitter/chairman.
• Being in a society is not an achievement for Thalia.

Current implementation

See above.

Desired implementation

See above.