Validate parsed ErgoTree header, check no bytes left unconsumed after ErgoTree is parsed

[greenhat]

Ref #677
Close #587

[coveralls]

Pull Request Test Coverage Report for Build 4113135832

• 120 of 137 (87.59%) changed or added relevant lines in 4 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.07%) to 63.482%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
ergotree-ir/src/ergo_tree/tree_header.rs	28	29	96.55%
ergotree-ir/src/chain/ergo_box/box_id.rs	0	2	0.0%
ergotree-ir/src/chain/json/ergo_box.rs	0	3	0.0%
ergotree-ir/src/ergo_tree.rs	92	103	89.32%

Files with Coverage Reduction	New Missed Lines	%
ergo-p2p/src/peer_database/in_memory.rs	1	85.71%
ergotree-ir/src/serialization/types.rs	2	84.97%

Totals
Change from base Build 4064537449:	0.07%
Covered Lines:	10100
Relevant Lines:	15910

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💛 - Coveralls