fix(true/false): print Usage line before about in --help (fixes #10279)

[leno23]

Summary

• Use a custom help template for true and false so --help starts with a Usage: line, matching GNU coreutils.

Test plan

• cargo run -p uu_false -- --help | head -1 shows Usage: false ...
• cargo run -p uu_true -- --help | head -1 shows Usage: true ...

Fixes #10279

Made with Cursor

[oech3]

This should be part of *.ftl files. Or translation is removed.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/tty-eof. tests/misc/tty-eof is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/date/resolution (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/misc/io-errors (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/tail/pipe-f (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/tail-n0f (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/unexpand/bounded-memory is now being skipped but was previously passing.