Fully-qualifiy Msf::MODULE_TYPES constants

MSP-11126

Fully-qualify `Msf::MODULE_TYPES`, `Msf::MODULE_ANY`,
Msf::MODULE_ENCODER`, `Msf::MODULE_EXPLOIT`, `Msf::MODULE_NOP`,
`Msf::MODULE_AUX`, `Msf::MODULE_PAYLOAD`, `Msf::MODULE_POST` so that
their usage isn't dependent on nested lexical scoping.