fix(mksh): implicit install requires printf

[FGrose]

Check for and install printf, when missing, and mksh is /bin/sh.

When these conditions apply,

1. host has ln -sf mksh /bin/sh, and
2. if a shell program is NOT specified, and
3. if NO modules are called with a dependency for the 99base module (where bash would be specified), then

resolve_deps() will install mksh, as the source for /bin/sh as in Script installs with a shebang.

Checklist

• [✔] I have tested it locally

Fixes #1530; finishes #1534.

[LaszloGombos]

@FGrose Can you think of a solution to move the fix out of dracut.sh into mksh dracut module instead ?

[FGrose]

@FGrose > Can you think of a solution to move the fix out of dracut.sh into mksh dracut module instead ?
@LaszloGombos
Superseded by #2368.