fix(url): unescape url before marshalling, in case it contains env vars

[kad-korpem]

Description

In case a URL in the config contains env vars, these were escaped by url.Parse, causing potential issues later. To maintain the env vars, url.PathUnescape has been added to the marshalling methods.

Type of change

• Bugfix

Checklist:

• I've double-checked the code in this PR myself
• I've left the code better than before (boy scout rule)
• The code is readable, comments are added that explain hard or non-obvious parts.
• I've expanded/improved the (unit) tests, when applicable
• I've run (unit) tests that prove my solution works
• There's no sensitive information like credentials in my PR