net/libngtcp2: Update to 1.2.0

• Switch to CMake for faster builds, it also additionally cleans up the port Makefile and removes the need for additional patching
• Disable OpenSSL requirement as it fails due to lack of QUIC support which is in 3.2
• Rearrange Makefile to follow Porters Handbook more closely and for readability

PR: 274782
Approved by: portmgr (maintainer timeout 2+ weeks)