Implemented simple new/edit methods for standalone fragments

Merge branch 'feature/extend_plan_details' into feature/occuring_answers

Added simple occurring answers implementation

Uncommented verify_authorized in StructuredAnswer controller

Reorganized structured answer routes

User can now choose & edit contact & principal investigator from the created person fragment list

Added StructuredAnswer policy & authorization

Small fix to the parent fragment update

Small fix, delete button should work for parterns & funding after the table is refreshed

Should be able to create a new Partner or Funding

Deleting a Partner or Funding should refresh the list properly

Funding & Partners should be editable

Changed Update & Delete buttons in Partners & Funding list

Added Funding form

First version of the Partners creation & edit form

Implemented a first version of the to_string method for JSON fragment

First working version of the new Plan details form

Fixed ethical_issue name in structured answer

Added classname to the schema form

Moved maDMP code from the roadmap codebase to the OPIDoR codebase

Merge branch 'dev' into feature/save_dmpdata_as_json

Removed schema presence validation for now

Updated fragment models according to data model

Multiple changes to Project & Meta fragments are saved ...

Persons fragments should be created only when they don't exist

Fixed project fragment generation when creating a plan

References to children fragment should be updated when creating or deleting a child fragment

Destroying a research output should destroy the associated json_fragment

Merge branch 'fix/seed' into dev

Added missing saving status for structured answers

STI column value should be more readable