Optimise copying of data inputs in npm_install and yarn_install

[Silic0nS0ldier]

repository_ctx.___ actions (e.g. spawning a process, working with files) are very slow vs. most other environments. To optimise copying data dependencies this PR refactors _copy_data_dependencies to;

1. Create an input files list and write it to a file (avoids the argument length limits).
2. Performs copy in a shell script using tar.

tar was selected as;

• Easy to preserve the desired directory structure (BSD cp only does this for directory copying, GNU cp can via --parents).
• Built in support for an inputs list via --files-from.

rsync would likely represent a more optimal solution, however I'm not very familiar with it. It may make sense as a follow up if there is sufficient room for improvement.

[christianscott]

LGTM