Add adding view environments

[josephmancuso]

This PR adds a new add_environment method onto the view class. this can be used to add Jinja2 environments to the code. Useful for packages that want to expand templates and supports better Masonite package to Masonite applications relationships.

This PR also adds significant improvements to how packages are structured after finally finding the documentation on Jinja2 loaders.

The new code can be used like so:

def boot(self, ViewClass):
     ViewClass.add_environment('dashboard/templates')

This will default to the Jinja2 PackageLoder. You can specify the loader explicitly:

from Jinja2 import FileSystemLoader
def boot(self, ViewClass):
     ViewClass.add_environment('dashboard/templates', loader=FileSystemLoader)

Many other minor tweaks to how Jinja2 environments are built