Tracks issued assets state and contextually validates issue actions and asset burns

[arya2]

This PR tracks issued assets in Zebra's state and uses that state to contextually validate issue actions and asset burns.

It still needs tests, additional documentation, cleanup, and to track information for creating split notes.

Review

This PR may be easier to review by commit.

[arya2]

@dmidem I think it would be simpler to keep the issued assets maps on each ContextuallyValidatedBlock partial relative to the previous block instead of making them partial relative to the finalized tip, but if they need to be relative to the finalized tip, copying the AssetBases for every block would multiply the non-finalized state's theoretical max memory use, so those should go in Arcs.

Suggested change

	/// Remove the History tree index at `height`.
	/// When a block with the provided `transactions` and partial `issued_assets` state is removed
	/// from the chain tip, revert its changes from the [`Chain`]'s partial issued assets state.
	///
	/// When a block is removed from the chain root to be committed to the finalized state, any
	/// assets in its partial `issued_assets` with an asset state matching the one in the chain's
	/// partial issued assets map is removed from the chain's partial issued assets map (since that
	/// it should match the finalized issued asset state.)

[dmidem]

Closed in favor of #29.