Ensure the record layer is responsible for calculating record overheads

Ensure the record layer is responsible for calculating record overheads

Don't calculate the potential record layer expansion outside of the
record layer. We move some code that was doing that into the record
layer.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19424)