Expose REST service to read training records by given filter

[emiovska]

Filter can by each field from the model

• [x] Filter by training name
• [x] Filter by training level

[Sofija777]

New GET services added

• GET service for filtering by name
• GET service for filtering by level

[RisteJovanoski]

I see that all the tasks are checked and that there is a pull request for this story. Maybe you forgot to move it to the Review/QA column?