Read-only mode

[ntarocco]

This feature request has been created after the implementation of @max-moser

Read-only mode can be used to implement a conditional read-only mode, e.g. enabled temporarily to make system migrations smoother.

Pull requests

• https://github.com/inveniosoftware/invenio-vocabularies/pull/231
• https://github.com/inveniosoftware/invenio-requests/pull/293
• https://github.com/inveniosoftware/invenio-communities/pull/830
• https://github.com/inveniosoftware/invenio-rdm-records/pull/1120
• https://github.com/inveniosoftware/invenio-records-permissions/pull/86
• https://github.com/inveniosoftware/invenio-users-resources/pull/57
• https://github.com/inveniosoftware/invenio-drafts-resources/pull/209