[Ontology] [Submissions pool] Enable Fellows to add specialties to submission

Feature Request

Description

Give a tool to Fellows and EdAdmin to add a specialty to submissions in the pool. This tool can be displayed in the Submission information tab of the pool entry, in the Ontological classification section. The tool should be available to any Fellow in the current submission's specialties before an EiC is assigned, and only to the EiC afterwards. The tool should always be available to EdAdmin.

When adding new specialty: the Fellowship of that submission should be immediately updated to include Fellows on the new specialty.

By policy, deleting specialties should not be allowed (at least for now).