Allow classes to be passed into Injector::inst()->load()

[n8-dev]

Issue:

Progress on #10533

Summary:

It appears there was a breaking change in #10265 that prevents anonymous classes (to override specific functions in tests) being passed into Injector::inst()->load().

Thus this is a breaking change from 4.10 to 4.11

Objective

This PR's purpose is to bring back this functionality, whilst keeping any speed gains from #10265

Spurred off @kinglozzer comments there, and conversation with @GuySartorelli in SS Users slack.

I have tested this locally with business logic, and this resolves the original issue.

Comments

As this adds another path through InjectionCreator it needs some unit tests.
I am not sure where is would be best to add this, doesn't appear to be a dedicated TestInjectionCreator file or anything.

Happy for someone else to write the tests or point me in the right direction.

Parent issue

• Breaking change in 4.11: Injector can't handle anonymous classes #10533

[emteknetnz]

@n8-dev thanks for your contribution - there's some changes I wanted to make on this. To better fit with our internal workflow I've opened a new pull-request that builds of this one here - I've put you down as a co-author in the single git commit in that pull-request

Thanks again