Separate the package in two parts to get less dependencies

[HrX03]

As of now flutter_quill has a lot of dependencies for the toolbar, i was wondering if the toolbar impl can just be moved to another optional package so if you want to implement your custom toolbar you don't have to depend on that many packges.

I'm eventually considering using the package for one of my apps but as of now the dependencies are the issue, i'd end up shipping more than i'd actually use

[singerdmx]

Submit a PR for that
Thanks

[singerdmx]

We will have only one package to ship
Two package is too much to manage