More optimized BANKED for SEQUENCE / IMAGES resources

[spotlessmind1975]

If you use BANKED to manage the loading of elements, and you used BANKED(1) to stay in the available space, then it is likely that a part of the slowness is due to the "swapping" process between memory expansion and resident ram. It would be necessary to introduce a copy mechanism of the "frame" that is needed, instead of the whole resource. In that specific case, we will always copy even when it has already been copied, but a smaller amount of bytes. To understand, if an image occupied 500 bytes per frame and there were 10 frames, instead of copying 5,000 bytes only once, 500 bytes would be copied every time PUT IMAGE is used. It would clearly be 10x faster than if I only had BANKED(1).

[spotlessmind1975]

Implemented for PC128OP.