tool_build/interface/command_help: added usage line and option help.
tool_build/interface: print usage & help direction with no/unrecognized command.
tool_build: made info & usage text macros.
tool_build/interface: commands: removed name prefix, untraced error logs.
error/assert: added prefix to assertion message.¹

1: It can be unclear to the uninitiated that the following line is
part of the assertion output, so it should be explicit.
tool_build/interface: removed long-form variants to bool switches.¹

1: Why have two? There're few switches, and they're easy to
understand. More concise with a single form, and it's less typing.