Alternative two-way reachability method

[daemontus]

This updates the symbolic reachability procedure such that if a set of avoid states is provided, it will run both forward reachability from the attractor pivot and backward reachability from the avoid states interleaved with each other. Consequently, the avoid states often expand very quickly and we can find an intersection much faster.

This solves a few extra benchmarks among the large random models (at the very least, NK2 n1280_3 and n2560_85). It shouldn't really impact models where we don't end up using the symbolic reachability.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
biobalm
_pint_reachability.py	61	50	18%	24, 40–54, 69–93, 101–146
control.py	114	14	88%	107, 119, 125, 129, 134, 143–159, 477, 480, 493
interaction_graph_utils.py	52	6	88%	11–13, 151–152, 222–223
petri_net_translation.py	149	12	92%	22–26, 79, 136, 234, 308–309, 333–334, 343, 452
space_utils.py	132	20	85%	26–28, 104–110, 133–139, 347–350, 414, 462
succession_diagram.py	391	74	81%	6, 123, 213–218, 231, 278–285, 389–396, 413–414, 424, 430, 546, 633–639, 755, 758, 853–867, 898–916, 948, 958, 961, 1001, 1008, 1059, 1077, 1199, 1385, 1396, 1404, 1447, 1459, 1464, 1470
symbolic_utils.py	32	5	84%	10, 39–44, 100, 128
trappist_core.py	184	23	88%	14–18, 55, 57, 92, 215, 217, 219, 254–256, 276–282, 340, 342, 372, 420, 422
biobalm/_sd_algorithms
expand_attractor_seeds.py	60	7	88%	6, 28, 42, 109–114, 119
expand_bfs.py	28	1	96%	6
expand_dfs.py	30	1	97%	6
expand_minimal_spaces.py	42	3	93%	6, 28, 42
expand_source_SCCs.py	111	16	86%	11–13, 50, 69, 77, 82, 103, 112, 120, 131, 140, 143, 167, 179, 242–243
expand_source_blocks.py	121	20	83%	10, 30, 42–45, 57, 67, 74, 79, 82, 141, 167, 176, 210–211, 215, 225, 231, 240
expand_to_target.py	31	3	90%	6, 38, 43
biobalm/_sd_attractors
attractor_candidates.py	265	90	66%	13–15, 26–27, 93, 101, 107–108, 130, 152, 187, 193–204, 223, 239–320, 325, 329, 335, 341, 356, 383, 388, 392, 398, 400–438, 511, 582–583, 684
attractor_symbolic.py	212	38	82%	6–7, 38–39, 57, 66–82, 85, 90, 171, 184–188, 199, 208, 240, 276, 306–308, 327, 337–339, 349, 358, 400, 420, 427
TOTAL	2104	383	82%

Tests	Skipped	Failures	Errors	Time
359	0 💤	0 ❌	0 🔥	58.341s ⏱️

[daemontus]

Merging, since tests are passing and this shouldn't mess with anything too important.