Fix node-gyp run time.

[otis]

Summary

• Fix node-gyp runtime:
  • Link node_modules to package's base directory because node-gyp and node.js packages in general, is looking for node_modules directory in its base directory.
  • Pull in www/npm as a runtime dependency, too, as node-gyp requires npm node_modules on run time,
• Build textproc/node-re2 without NODE_PATH explicitly defined.

Test Plan

poudriere results:
https://freebsd-current.builder.wilbury.net/build.html?mastername=13cgx64-default&build=2021-03-16_13h22m23s

[otis]

Fix actual linking

[osa]

LGTM.