feat: add From<StringAdapter> trait for MemoryAdapter

[liulifox233]

• feat: add From trait for MemoryAdapter
• feat: add from_str() function for MemoryAdapter
• feat: add some unit tests for MemoryAdapter

[github-actions]

Benchmark for c1d9378

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Test	PR Benchmark	Master Benchmark	%
b_benchmark_rbac_model_large	10.7±0.06ms	9.9±0.08ms	+8.08%
benchmark priority model	4.2±0.10µs	4.3±0.06µs	-2.33%
benchmark_abac_model	2.5±0.06µs	2.5±0.05µs	0.00%
benchmark_basic_model	3.7±0.07µs	3.8±0.04µs	-2.63%
benchmark_key_match	6.8±0.16µs	7.0±0.29µs	-2.86%
benchmark_raw	0.0±0.00ns	0.0±0.00ns	NaN%
benchmark_rbac_model	5.9±0.06µs	6.2±0.08µs	-4.84%
benchmark_rbac_model_medium	912.8±6.66µs	879.3±7.50µs	+3.81%
benchmark_rbac_model_with_domains	5.8±0.06µs	5.9±0.07µs	-1.69%
benchmark_rbac_with_deny	8.2±0.12µs	8.7±0.09µs	-5.75%
benchmark_rbac_with_resource_roles	4.4±0.19µs	4.5±0.14µs	-2.22%
benchmark_role_manager_large	4.7±0.03ms	4.5±0.02ms	+4.44%
benchmark_role_manager_medium	301.9±2.34µs	308.8±20.34µs	-2.23%
benchmark_role_manager_small	93.1±1.21µs	90.7±1.48µs	+2.65%