Currently ports are manually using dependency to www/node , www/node16, ....
Often you must use the same node version for several ports, else it will cause compile or runtime problems.
This commit will add a new default node version which currently points to the last LTS version (16).
If a port depends on node, a simple:
can be added. It is also possible to define a specific version:
I will commit this in two commits, one added the ports .mk files and one commit modifying to ports displayed here, I just included it into one review to have the big picture here.