feat: allow changing opportunity type

[kiborrdis]

Description

Allow changing opportunity type via PATCH /opportunity/:id

Related Issues

Closes #730

Changes

• Add opportunity_type to schema
• Add passthrough of opportunity_type in patch data parsing
• Add creation on new accompanying record for opportunity, if there is none and type is being changed to accompanying

Checklist

• opportunity_type changes if present in patch data
• opportunity_type remains the same if not present in patch data
• if opportunity_type is changed to accompanying, accompanying record is created
• if there is accompanying in patch data, and opportunity_type is not accompanying, record is not created