COMMAND takes char_or_var_vl, so an option's name is often a variable
and only known at run time. Two consequences, both verified against the
C runtime:
Option text is trimmed before it goes on the wire - a CHAR(20) variable
holding "Customer" must not reach the client as "Customer ".
The menu title is deliberately NOT trimmed, because the C does not trim
it either.
SHOW OPTION, HIDE OPTION and NEXT OPTION address an option by its text
rather than its position, so they take a string. The enum still names
the COMMAND clause for dispatch - the clause count is fixed by the
source however dynamic the names are - and TextOf() maps a clause back
to its current text for callers that only hold the enum.
