Implement more builtins

[reubeno]

No description provided.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (ns)	Test/PR (ns)	Delta (ns)	Delta %
expand_one_string	3352 ns	3350 ns	-2 ns	🟢 -0.06%
instantiate_shell	64334 ns	65319 ns	+985 ns	🟠 +1.53%
instantiate_shell_with_init_scripts	47884434 ns	47433843 ns	-450591 ns	🟢 -0.94%
parse_bash_completion	6671686 ns	6721907 ns	+50221 ns	🟠 +0.75%
parse_sample_script	10905 ns	10885 ns	-20 ns	🟢 -0.18%
run_echo_builtin_command	104899 ns	104053 ns	-846 ns	🟢 -0.81%
run_one_builtin_command	121428 ns	122096 ns	+668 ns	🟠 +0.55%
run_one_external_command	1817257 ns	1834200 ns	+16943 ns	🟠 +0.93%
run_one_external_command_directly	1034793 ns	1032262 ns	-2531 ns	🟢 -0.24%

Code Coverage Report

Package	Base Coverage	New Coverage	Difference
cli.src	🟠 73.95%	🟠 73.95%	⚪ 0%
interactive-shell.src	🟢 76.02%	🟢 76.02%	⚪ 0%
parser.src	🟢 85.88%	🟢 85.88%	⚪ 0%
shell.src	🟢 81.25%	🟢 81.36%	🟢 0.11%
shell.src.builtins	🟠 69.06%	🟠 70.61%	🟢 1.55%
Overall Coverage	🟢 79.63%	🟢 79.95%	🟢 0.32%

Minimum allowed coverage is 0%, this run produced 79.95%