fix(fms): merge constraints when stringing

[BlueberryKing]

Fixes #[issue_no]

Summary of Changes

Fixes an issue where constraints at the IAF would be discarded when the approach was string to the arrival.

Also removes a console.log I accidentally left in in a previous PR.

Screenshots (if necessary)

Before:

After:

References

Additional context

Discord username (if different from GitHub):

Testing instructions

Try entering different destinations, arrivals and approaches, make sure that the constraints at the IAF always matches the charts.

How to download the PR for QA

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4. Click on either flybywire-aircraft-a320-neo or flybywire-aircraft-a380-842 download link at the bottom of the page