[14] Save lessons

[danielferecatu]

What does it fix?

WIP Issue #14

Closes #XXX
Moved form #62

How has it been tested?

Ran tests with dotnet test:

Passed! - Failed: 0, Passed: 2, Skipped: 0, Total: 2, Duration: 247 ms - TeacherWorkout.Specs.dll (net8.0)

Via UI:

query AllLessons {
  lessons {
    edges {
      node {
        id
        title
      }
    }
  }
}

mutation LessonSave($input: LessonSaveInput!) {
    lessonSave(input: $input) {
        lesson {
            title
        }
    }
}

{
  "input": {
    "lessonId": 0
  }
}

Te rog sa verifici daca mai sunt necesare modificai in fisierul de statup privind user, ca am modificarile in fisier.

[danielferecatu]

The implementation is not complete. Do not merge yet.