[QUIC] Call `LocalCertificateSelectionCallback` before handshake

[karelz]

Call client-side callback LocalCertificateSelectionCallback before handshake -- as a workaround of #65439

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Issue Details

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Call client-side callback LocalCertificateSelectionCallback before handshake -- as a workaround of #65439

Author:	karelz
Assignees:	rzikm
Labels:	enhancement, area-System.Net.Quic
Milestone:	7.0.0