Replacing defer with testhelpers.Close() part 1

What does this MR do?

I am planning to solve this issue in at least 2 MR's. This MR specifically focuses on acceptance tests. I have changed the code so that all Body's will be closed using testhelpers.Close() function.

issue: #607 (closed) MR part 2: !690 (closed)

TODO

• I added the Changelog trailer (e.g. Changelog: added) to the commits that need to be included in the changelog
• I added unit tests or they are not required
• I added acceptance tests or they are not required
• I added documentation (or it's not required)
• I followed code review guidelines
• I followed Go Style guidelines