Changing documentation for validaiton methods to make room for the new changes
Implemented executing a callable for determine if field can be allowed to be empty
Fixed isEmptyAllowed() method
Adding tests for the new conditional checking feature in the validator
Automatically setting the entity provider inside EntityContext

This was required as now the outcome of isEmptyAllowed could change based on
what is contained inside the entity object
Ensuring the right entit is passed as provider in EntityContext
Removing unused property
docs: Remove obsolete references to RequestHandlerComponent::setContent()
Component: Include LogTrait to allow calling log() as in 2.x
Merge pull request #3794 from rchavik/3.0-misc

3.0 misc
Micro optimize Route.

Calling empty() instead of a userland function is a teeny tiny bit
faster.
Add ScopedRouteCollection

Pull the changes from my prototype branch into a less experimental
branch.
Start adding tests for ScopedRouteCollection

Make extensions an instance property instead of a global static that is
pulled in on each connected route. Having instance properties will allow
scopes to have different extensions if desired.
Add tests for redirect().
Add ability to set Router::scopes() and use prefix()

Fix problems and add tests.
Add basic tests for Router::scope().
Add tests for plugin() method.
Add test for parse().
Add tests for match().
Add tests for resource().

Still need a few more for the various connected routes.