Escape user supplied code before inserting as a POST parameter

What does this MR do?

The code parameter should be escaped before being inserted into POST query parameters. This MR fixes a non-exploitable parameter injection.

TODO

• I added the Changelog trailer (e.g. Changelog: feature) 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