lib: reduce use of strncpy

lib: reduce use of strncpy

- bearssl: select cipher without buffer copies
- http_aws_sigv4: avoid strncpy, require exact timestamp length
- http_aws_sigv4: use memcpy isntead of strncpy
- openssl: avoid strncpy calls
- schannel: check for 1.3 algos without buffer copies
- strerror: avoid strncpy calls
- telnet: avoid strncpy, return error on too long inputs
- vtls: avoid strncpy in multissl_version()

Closes #12499