Exclude enterprise licensed plugins from the all package

[sagikazarmark]

Currently there is no way to import all open source plugins. I'd argue that people who used the public/all package before may not be aware that some of the plugins now have a different license.

Would be nice to move those plugins out into an enterprise package.

[emaxerrno]

good idea.

[Jeffail]

Hey @sagikazarmark, good shout, I've started off by breaking out two new packages with explicit licensing, details here: #2621 (comment)

And the plugin example repo is updated to show how to build an entirely FOSS distribution: https://github.com/benthosdev/benthos-plugin-example