Enable reading glob patterns to combine mutliple files in a directory

[akaIDIOT]

Initially tested with /etc/{name}/{name}{suffix}.d/ and *, succesfully matching the files in /etc/apt/apt.conf.d/ (though apt uses its own config file format that won't parse, but that's another thing).

[github-actions]

Comparing median (lower is better) metric of benchmarks between this PR's target (562ed1c) and the HEAD of this PR (ddf2ebe):

	3.10	3.11	3.12	3.13	3.14	3.15	PyPy 3.10	PyPy 3.11
test_benchmark_get	-0%	-2%	+0%	-1%	-0%	-2%	+0%	+2%
test_benchmark_get_dotted	-4%	-1%	-1%	-1%	-1%	-1%	+3%	+0%
test_benchmark_getattr	+0%	+3%	+1%	-1%	+1%	-2%	-1%	-1%
test_benchmark_getitem	+1%	+1%	+2%	-1%	+0%	-1%	-0%	+1%
test_benchmark_getitem_dotted	-2%	-2%	-0%	-0%	+0%	-2%	+6%	+3%
test_benchmark_init_full_overlap	-1%	-3%	-2%	-2%	-1%	-0%	+0%	-0%
test_benchmark_init_no_overlap	-2%	-2%	-1%	-2%	-1%	+2%	-1%	-0%
test_benchmark_init_partial_overlap	-0%	-4%	-0%	-2%	-1%	+0%	-0%	+0%
test_benchmark_match_mapping	-1%	+2%	-0%	-2%	+0%	-3%	-2%	-2%
test_benchmark_reference_chain	+0%	-2%	-0%	-0%	-1%	-2%	+2%	+5%
test_benchmark_splat_args	+2%	-2%	+2%	-1%	-0%	-1%	-1%	+0%
test_benchmark_spread_kwargs	-3%	-1%	-3%	+0%	-0%	-1%	+1%	+1%

(This comment will be updated on subsequent pushes)