cyassl,curl,libustream-ssl: rename every `cyassl` to `wolfssl`

cyassl,curl,libustream-ssl: rename every `cyassl` to `wolfssl`

This is to eliminate any ambiguity about the cyassl/wolfssl lib.

The rename happened some time ago (~3+ years).
As time goes by, people will start to forget cyassl and
start to get confused about the wolfSSL vs cyassl thing.

It's a good idea to keep up with the times (moving forward).

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>