test: add a shim function for the apps's opt_legacy_okay() function Reviewed-by: Tomas Mraz <tomas@openssl.org> (Merged from https://github.com/openssl/openssl/pull/16022)
test: rename apps_mem.c to be apps_shims.c in anticipation of additonal functions Reviewed-by: Tomas Mraz <tomas@openssl.org> (Merged from https://github.com/openssl/openssl/pull/16022)
