fix(API): Fix board API details parameter to work as expected

[nickvergessen]

• Resolves: api/v1.0/boards?details=true does not return the labels and stacks anymore, breaking the Android app #4517
• Target version: main

Summary

Before ?details=true in the URL resulted in string "true" and therefore did not match $details === true which was brought in by b19b779 but it matched the old $details logic.

Defining the parameter as bool (like it was done in the other touched controller methods) gives the actual boolean to the controller fixing the comparison

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Documentation (manuals or wiki) has been updated or is not required

[nickvergessen]

/backport to stable26

[nickvergessen]

Also applied it on our instance as a patch and the Android app works again :)