Provide specific objects on individual invocation

[g105b]

We already have this:
https://github.com/PhpGt/ServiceContainer/blob/master/src/Injector.php#L26C24-L26C24

This $extraArgs parameter is currently not used anywhere, as I've never found a use for matching a parameter by string.

I think we should drop this functionality completely, and replace the function of $extraArgs.

At the point of invocation, I would like to be able to pass a specific object, so we can have DomTemplate Components with their own PHP, solving the issue described in phpgt/DomTemplate#331

When a DomTemplate Component is detected, the invoke function of the Injector should be called with a few extra indices of $extraArgs: The Gt\Dom\Element of the component, and a new ComponentBinder (the same as a DocumentBinder, but with a pre-constrained context element of the current component).

This would be a fabulous addition to WebEngine development!

[g105b]

It would be useful if the extraArgs overwrote the Injector when looking for a matching class instance. If there was already a XYZ class in the ServiceContainer, providing a new instance of XYZ to extraArgs would prefer to use this one.

This means we could provide one of two things:

1. provide a default instance of the ComponentBinder so when there's no specific instance provided, an exception is thrown saying something like "A ComponentBinder can only be used within a Component element's go/do functions".
2. Rename the DocumentBinder completely to just be a Binder... then the Binder itself can be overridden when in the context of a Component.

[g105b]

I like how just using a Binder everywhere enforces encapsulation, but maybe some components should be able to bind data outside of their own component element? Maybe? Maybe not... maybe they should just have access to the HTMLDocument if they need to be heavy handed with their encapsulation... (?)

[g105b]

More details on the above at phpgt/DomTemplate#470