resume content to user remodel

# Assumptions
- **ResumeEntity** keeps a reference to the IDs of a user's content that apply to that resume (list of references for the experiences, projects, contact methods, skills, ... that are shown in that **resume**
- **UserEntity** keeps the content of all experiences, projects, contact methods, skills, ... that are associated to that **user**
- At this point we can keep the API endpoints the same, which means keeping the DTOs the same
- Change **ResumeService** to interacting with **ResumeRepository** and **UserRepository**