vdir: make vdir an alias of ls to resolve missing ftl

[NatsuCamellia]

Fixes #10363

Make vdir an alias of ls just as dir is an alias of ls, so vdir can access the ftl files of ls. Also merged vdir's ftl strings into ls's.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tty/tty-eof (passes in this run but fails in the 'main' branch)

[codspeed-hq]

CodSpeed Performance Report

Merging this PR will not alter performance

_{Comparing NatsuCamellia:vdir-alias-ls (da5c690) with main (6f955da)}

Summary

✅ 142 untouched benchmarks
⏩ 180 skipped benchmarks¹

Footnotes

1. 180 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[oech3]

Would you move issue tag to 1st comment with the word "closes" and fix cargo clippy?

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/seq/seq-epipe is now passing!

[oech3]

Hmm, This PR looks valid, but when I applied same change for #10549 , it was still broken.

[oech3]

Please drop changes for split cmd.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[NatsuCamellia]

I dropped the changes for split and merged from main branch again.
I'm new to here, thank you for your patience!