[RFC007] Add Seal and Unseal to the new AST primops

[yannham]

While working on #2083, I realized that we do need the seal and unseal primitives (which were initially discarded as only a run time thing), since the implementation of the builtin contracts is written in pure Nickel and use those operations.

This PR adds the missing variants to Primop and missing conversion as well in bytecode::ast::compat.

[github-actions]

Bencher Report

Branch	rfc007/add-missing-seal-ops
Testbed	ubuntu-latest

Click to view all benchmark results

Benchmark	Latency	nanoseconds (ns)
fibonacci 10	📈 view plot 🚷 view threshold	479,950.00
foldl arrays 50	📈 view plot 🚷 view threshold	1,663,400.00
foldl arrays 500	📈 view plot 🚷 view threshold	6,681,000.00
foldr strings 50	📈 view plot 🚷 view threshold	7,055,600.00
foldr strings 500	📈 view plot 🚷 view threshold	61,825,000.00
generate normal 250	📈 view plot 🚷 view threshold	44,675,000.00
generate normal 50	📈 view plot 🚷 view threshold	1,986,300.00
generate normal unchecked 1000	📈 view plot 🚷 view threshold	3,329,500.00
generate normal unchecked 200	📈 view plot 🚷 view threshold	769,200.00
pidigits 100	📈 view plot 🚷 view threshold	3,179,400.00
pipe normal 20	📈 view plot 🚷 view threshold	1,476,400.00
pipe normal 200	📈 view plot 🚷 view threshold	10,066,000.00
product 30	📈 view plot 🚷 view threshold	827,690.00
scalar 10	📈 view plot 🚷 view threshold	1,501,000.00
sum 30	📈 view plot 🚷 view threshold	825,130.00

🐰 View full continuous benchmarking report in Bencher