fix: Export injection token used by plugins

[PeterStaev]

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• Tests for the changes are included.

What is the current behavior?

The TEMPLATED_ITEMS_COMPONENT injection token is missing from the export, thus preventing ability to create plugins/other components that extend the TemplatedItemsComponent

What is the new behavior?

The TEMPLATED_ITEMS_COMPONENT is re-exported

Fixes/Implements/Closes #[Issue Number].

[PeterStaev]

@NathanWalker could we get this reviewed, merged and released with this weeks patches? Would love to finish updating my plugins 😉