Split aggregate bindings into core & modules

A first step in splitting bindings: split the aggregate bindings.
Will followup by splitting bindings_core and bindings_modules .gyp files
and splitting individual bindings.

R=haraken
BUG=358074

Review URL: https://codereview.chromium.org/256443003

git-svn-id: svn://svn.chromium.org/blink/trunk@172477 bbb929c8-8fbe-4397-9dbb-9b2b20218538