Sakari/enc/fix register page

[Skoivumaki]

Requested changes done on issue #76

• we should remove fields: name, backpack capacity and unique identifier
• confirming text should be changed to -> "vakuutan että olen yli 13 vuotias tai minulla on vanhempieni lupa osallistua pelin sosiaaliseen toimintaan"'
• confirming text should be translated

Stuff done:

• Updated consent field text locales and fixed on submit error text
• Removed fields from form: name, backpack capacity and unique identifier (API requires backpackCapacity, uniqueIdentifier and name fields to be filled. Used username as uniqueIdentifier and name to POST 201.)
• Updated auth model/schema to include above13 boolean
• Tested to be working
• API requires backpackCapacity, uniqueIdentifier and name fields to be filled. Used username as uniqueIdentifier and name to post 201.