Fixes #8838
1. Summary
It seems [this PR](https://github.com/twentyhq/twenty/pull/8614) caused
the issue. We added a plus sign on front-end when the
[callingCode](c735026f6c/packages/twenty-front/src/modules/ui/field/display/components/PhonesDisplay.tsx (L70))
retrieved from back-end already has a plus sign.
2. Solution
@guillim Please let me know if I missed a case where the plus sign is
not there for the `callingCode`. If so, I think we should check whether
or not `callingCode` has a leading plus sign on front-end before adding
it. For now, I just removed the code that appends a plus sign on
front-end.
3. Screenshots

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Co-authored-by: guillim <guigloo@msn.com>
Co-authored-by: Guillim <guillim@users.noreply.github.com>
Co-authored-by: Weiko <deniaud.corentin@gmail.com>