[BUG]: "Time" in model page is incorrect w.r.t. AMR

[liunelson]

Describe the bug

• "Time" has no property called "name" in the model AMR and the "add a name" field should be removed
• "Time" also has no property called "description" or any concept; the "Add description" and "Concept [Search concepts]" should be removed
• The "Add a time unit" field should read first from the model AMR to see if there is already a time unit model.time.units.expression (model.time.units.expression = "day" by default -> map it to "Days")

Test model