fix: PropertyValueCountTrigger now observes PropertyInitializedEvent

[RobertJacobsonCDC]

Fixes #922, a possible underflow in PropertyValueCountTrigger.

This PR is stacked on #1025.

[github-actions]

Benchmark Results

Hyperfine

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
large_sir::baseline	3.5 ± 0.1	3.4	3.6	1.00
large_sir::baseline_households	3.5 ± 0.1	3.4	3.6	1.01 ± 0.02
large_sir::entities	7.9 ± 0.1	7.6	8.3	2.28 ± 0.05
large_sir::households	8.0 ± 0.6	7.6	10.6	2.32 ± 0.19

Criterion

Regressions (slower)

Group	Bench	Param	Change	CI Lower	CI Upper
indexing	with_query_results_indexed_multi-property_entities		42.543%	39.932%	44.968%
sample_entity	sample_entity_whole_population	1000	31.604%	27.584%	36.017%
sample_entity	sample_entity_whole_population	10000	29.286%	25.385%	33.148%
sample_entity	sample_entity_whole_population	100000	26.932%	22.546%	31.202%
indexing	query_people_count_indexed_multi-property_entities		23.730%	21.816%	26.028%
large_dataset	bench_query_population_multi_indexed_entities		20.230%	17.205%	23.162%
counts	multi_property_unindexed_entities		17.679%	16.337%	18.936%
large_dataset	bench_query_population_derived_property_entities		6.928%	5.628%	8.278%
sampling	sampling_multiple_unindexed_entities		3.201%	2.778%	3.597%
examples	example-births-deaths		2.530%	2.091%	2.853%
examples	example-basic-infection		2.017%	1.511%	2.620%
sampling	sampling_single_unindexed_concrete_plus_derived_entities		1.790%	1.360%	2.214%

Improvements (faster)

Group	Bench	Param	Change	CI Lower	CI Upper
counts	concrete_plus_derived_unindexed_entities		-20.173%	-21.095%	-19.032%
sample_entity	sample_entity_single_property_indexed	10000	-19.648%	-21.041%	-18.182%
sample_entity	sample_entity_single_property_indexed	100000	-17.151%	-20.753%	-13.696%
counts	single_property_unindexed_entities		-15.541%	-16.927%	-13.967%
large_dataset	bench_query_population_multi_unindexed_entities		-8.921%	-10.782%	-7.118%
large_dataset	bench_match_entity		-6.911%	-7.297%	-6.511%
sample_entity	sample_entity_single_property_unindexed	100000	-5.015%	-6.820%	-3.052%
indexing	query_people_multiple_individually_indexed_properties_entities		-3.301%	-3.431%	-3.169%
counts	multi_property_indexed_entities		-3.299%	-4.509%	-2.119%
counts	reindex_after_adding_more_entities		-3.205%	-3.711%	-2.809%
sample_entity	sample_entity_single_property_unindexed	1000	-3.146%	-3.540%	-2.732%
indexing	query_people_count_multiple_individually_indexed_properties_enti		-2.820%	-2.924%	-2.705%
sample_entity	sample_entity_multi_property_indexed	100000	-2.211%	-3.208%	-1.169%
counts	index_after_adding_entities		-2.204%	-2.541%	-1.898%
sampling	sampling_single_l_reservoir_entities		-1.812%	-2.140%	-1.509%
indexing	query_people_count_single_indexed_property_entities		-1.687%	-2.141%	-1.294%

Unchanged / inconclusive (CI crosses 0%)

Group	Bench	Param	Change	CI Lower	CI Upper
sample_entity	sample_entity_single_property_indexed	1000	-2.024%	-3.431%	-0.495%
large_dataset	bench_filter_unindexed_entity		-2.014%	-4.969%	0.741%
sample_entity	sample_entity_multi_property_indexed	10000	-1.759%	-2.944%	-0.608%
sample_entity	sample_entity_multi_property_indexed	1000	-1.068%	-2.765%	0.616%
sampling	count_and_sampling_single_unindexed_concrete_plus_derived_entiti		-1.012%	-1.414%	-0.599%
sampling	sampling_single_known_length_entities		-0.916%	-1.181%	-0.668%
indexing	with_query_results_multiple_individually_indexed_properties_enti		0.824%	0.300%	1.373%
indexing	with_query_results_single_indexed_property_entities		-0.585%	-0.992%	-0.209%
indexing	query_people_indexed_multi-property_entities		-0.566%	-1.087%	-0.149%
large_dataset	bench_query_population_property_entities		-0.460%	-1.416%	0.284%
sampling	sampling_multiple_l_reservoir_entities		-0.405%	-0.593%	-0.229%
algorithm_benches	algorithm_sampling_multiple_l_reservoir		-0.387%	-0.761%	0.032%
sample_entity	sample_entity_single_property_unindexed	10000	0.370%	-0.245%	0.913%
algorithm_benches	algorithm_sampling_multiple_known_length		0.325%	-0.207%	1.147%
sampling	count_and_sampling_single_known_length_entities		0.307%	-0.325%	1.048%
counts	single_property_indexed_entities		0.282%	-0.015%	0.682%
algorithm_benches	algorithm_sampling_single_known_length		0.192%	-1.480%	1.789%
large_dataset	bench_query_population_indexed_property_entities		0.164%	-0.164%	0.618%
large_dataset	bench_filter_indexed_entity		0.140%	-1.606%	1.783%
algorithm_benches	algorithm_sampling_single_l_reservoir		-0.086%	-0.453%	0.231%
sampling	sampling_single_unindexed_entities		-0.083%	-0.448%	0.187%
indexing	query_people_single_indexed_property_entities		-0.072%	-0.204%	0.029%
algorithm_benches	algorithm_sampling_single_rand_reservoir		-0.046%	-0.198%	0.087%
sampling	sampling_multiple_known_length_entities		-0.043%	-0.287%	0.206%

Not Compared (no baseline yet)

Group	Bench	Reason
(none)