Remove entanglement forging

[caleb-johnson]

Nothing in Qiskit-Extensions should rely on the old Qiskit application modules, so we must remove Entanglement Forging from this repository. We can add it to qiskit-community in a standalone repository if we want.

[coveralls]

Pull Request Test Coverage Report for Build 7849542895

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.3%) to 93.75%

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Totals
Change from base Build 7849519735:	1.3%
Covered Lines:	2430
Relevant Lines:	2592

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💛 - Coveralls

[caleb-johnson]

Trying to track down what is causing this pandoc warning, I assume it's one of our notebook deps but not sure.

Other than that, this is ready for review. If we can get this and #480 removed, we can merge #475 and release. We could also clean up some deprecated packages as well before releasing.