refactors es_features to eliminate redundancy and improve maintainabi…

[dmanlfc]

…lity.

• the previous structure required manually copy-pasting a large list of shared: features for nearly every standalone emulator. this made adding or removing a common feature a tedious and error-prone process.
• with this change an inheritance model has been implemented: the global: shared: list is now a small, base template of truly universal features (power, video, decorations) that all emulators inherit automatically. libretro-specific features (shaders, latency reduction, AI, etc.) have been moved out of global and are now added to the libretro emulator via a shared_include: list. standalone emulators now only need to specify their differences from the base global set using shared_include: (to add features) or shared_exclude: (to remove them).

the batocera-es-system script has been updated to handle this new logic, calculating the final feature set for each emulator.

[dmanlfc]

@bryanforbes is seeking a better approach