test(parser): snapshot testing with expect_test

[39555]

expect_test is minimalistic library from the rust-analyzer project that does not require a lot of learning. It can update both inline snapshots and snapshots from files by running UPDATE_EXPECT=1 cargo test. TTo achieve comparable functionality to insta I've added serde_yaml for serialization although I don't particularly like using serde here because it doesn't include type names. A similar limitation to insta is that the snapshot file doesn’t include the input.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
expand_one_string	3.46 μs	3.46 μs	-0.00 μs	⚪ Unchanged
instantiate_shell	60.11 μs	60.35 μs	0.24 μs	⚪ Unchanged
instantiate_shell_with_init_scripts	33695.05 μs	34763.93 μs	1068.88 μs	🟠 +3.17%
parse_bash_completion	2973.75 μs	2864.48 μs	-109.27 μs	⚪ Unchanged
parse_sample_script	4.30 μs	4.25 μs	-0.06 μs	🟢 -1.37%
run_echo_builtin_command	91.72 μs	92.83 μs	1.11 μs	⚪ Unchanged
run_one_builtin_command	109.12 μs	111.63 μs	2.51 μs	⚪ Unchanged
run_one_external_command	2105.38 μs	2032.12 μs	-73.26 μs	🟢 -3.48%
run_one_external_command_directly	1035.12 μs	1030.67 μs	-4.45 μs	⚪ Unchanged

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/shell.rs	🟢 77.45%	🟢 78.01%	🟢 0.56%
brush-parser/src/parser.rs	🟢 99.14%	🟢 99.21%	🟢 0.07%
brush-shell/src/main.rs	🟢 90.26%	🟢 90.91%	🟢 0.65%
Overall Coverage	🟢 74.34%	🟢 74.54%	🟢 0.2%

Minimum allowed coverage is 70%, this run produced 74.54%

[39555]

The second commit contains snapshots in ron format. It looks better with the struct names