Revert "Port Exponential Law proofs from HoTT-categories"

This reverts commit b159e9710b2b3b6f9966ddbf67180d0c377a424b.

Conflicts:

	theories/categories/ExponentialLaws/Law2/Law.v
	theories/categories/ExponentialLaws/Law3/Law.v
	theories/categories/ExponentialLaws/Law4/Law.v