ECS and Audio rework

[mokiat]

Changes

ECS

A full rewrite of the game/ecs package. It now uses archetypes in order to position components linearly in memory. The API should be slightly more user-friendly - previous approach resulted in the need to wrap the ECS scene with a custom one with helper functions for getting and setting various components. This API makes those changes more direct, though the usage of closure functions for mutations is required (in order to make use of generics).

Audio

The mid-level core/audio package now exposes more features (buses, filters, effects) to be used by the game engine in the future.

Others

• Bumps Go version to 1.26
• Bumps dependencies
• Visibility fix in hierarchy where parent visibility is taken into account
• Improvements to Graph animation node
• Add a Reverse animation node
• Minor godoc improvements
• Minor gh-pages docs improvements