rgbds-style inline macro definitions

[yenatch]

Currently, adding and using a new macro in kanzure/pokecrystal requires the user to add a class to pokemontools/crystal.py.

Sometimes using a macro is the easiest way to arrange arbitrary data structures. For that purpose the macro does not need to be persistent and is best defined inline. bentley/rgbds already lets you do this, like so:

move: MACRO
        db \1 ; animation
        db \2 ; effect
        db \3 ; power
        db \4 ; type
        db \5 * $ff / 100 ; accuracy (percent)
        db \6 ; pp
        db \7 * $ff / 100  ; effect chance (percent)
ENDM

        move POUND, EFFECT_NORMAL_HIT, 40, NORMAL, 100, 35, 0

Apparently depending on rgbds is undesirable, and depending on pokemontools is not. In that case, this should be implemented in pokemontools.