State management and configuration implementations
Single Responsibility: Handle figure state, configuration, property accessors, animation support, and backend operations. Extracted from fortplot_figure_core_impl to maintain file size compliance.
── State management ──────────────────────────────────────────────
── Property accessors ────────────────────────────────────────────
── Animation support ─────────────────────────────────────────────
── Backend operations ────────────────────────────────────────────
── Range accessors ───────────────────────────────────────────────