[PCover] Update symmetry search, add concrete values

[aman-goel]

Updates include:

[PCover]

• Add experimental option to limit size of pending tasks queue used for arbitrary back-jumping.
• Adds storing concrete values directly for explicit-state search
• Updates symmetry dependency tracking to now use concrete values directly.
• Update how symmetry tracking is done with dependent fields
• Adds counting how many branches pruned with symmetry aware search
• Reverts commit f8c7bc3 to bring back choosing directly over composites instead of indexing
• Rename executions to schedules in logs/stats

[PSym] Bump version