WIP: Resolve "Button repeat for x weeks broken"

What does this mr do?

The repeat lab for x weeks did not work properly and threw errors. Also fixed the repeat lab for x+1 weeks bug.

Actions taken to fix bug

Save the lab before repeating the lab, repeating the lab x-1 times instead of x times because the initial lab is also added. Made the value of the field in the form required and set a min max.

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made and the bug I fixed.
• A test was created to test the bug.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #325 (closed) Closes #124 (closed)