Use kmacro-decision-named-macros in kmacro-decision-menu

Altered items:
kmacro-decision-menu
New function kmacro-decision-name-last-macro

Also refactor kmacro-decision-menu to use read-key-menu
Alias kmacro-name-last-macro to kmacro-decision-name-last-macro

Altered items:
kmacro-decision-named-macros,
kmacro-decision-name-last-macro, kmacro-decision-menu,
kmacro-name-last-macro, kmacro-decision
Handle nil return from read-key-menu

Altered items:
kmacro-decision