Prepare for syncing with upstream

[rushilmehra]

• Support linking with a runtime cpp library

  As of https://boringssl-review.googlesource.com/c/boringssl/+/66288, libssl allows a C++ runtime dependency. As such, we need to link with a cpp runtime library. Implementation is inspired heavily from https://github.com/google/boringssl/commit/54c956b2e668e11c75f1ee0367f1b3a0ad28eff9. Before releasing this change, we'll need to figure out a way to support this for windows.

• Fix bug with accessing memzero'd X509StoreContext in tests

  As of https://boringssl-review.googlesource.com/c/boringssl/+/64141, X509_STORE_CTX_cleanup will zero the memory allocated to the X509_STORE_CTX. Because X509StoreContextRef::init invokes X509_STORE_CTX_cleanup once the with_context closure has finished, calling X509StoreContextRef::verify_result (or any API really) is going to be invalid because memory has been zerod out. This is a pretty big footgun, so maybe we should consider screaming a bit louder for this case.

This patch doesn't sync with upstream yet, because all of our patches break due to upstream directory structure changes, and the RPK patch needs to be completely reworked