CMake: convert all LWS_USE_... to LWS_WITH_...

Almost all the CMake options begin with LWS_WITH_..., but many of the
symbols passed to lws are LWS_USE_... , this causes neededless confusion,
compounded by the fact that a few CMake options also begin with
LWS_USE_.

This patch globally converts all LWS_USE_... to LWS_WITH_..., so there
is only one prefix to remember in both CMake and the code.

The affected public CMake options are

LWS_USE_BORINGSSL     ->  LWS_WITH_BORINGSSL
LWS_USE_CYASSL        ->  LWS_WITH_CYASSL
LWS_USE_WOLFSSL       ->  LWS_WITH_WOLFSSL
LWS_USE_MBEDTLS       ->  LWS_WITH_MBEDTLS
LWS_USE_BUNDLED_ZLIB  ->  LWS_WITH_BUNDLED_ZLIB