glutin_wgl_sys breaking changes

Expose `Egl` and `Glx` raw API functions on `Egl` and `Glx` displays.

Bump `windows-sys` from `0.48.0` to `0.52.0`.

Fixed handling of `Robustness::NoError` and `debug` attribute when building context.

**Breaking:** `.*SurfaceAccessor` traits got removed; their methods now on respective `.*GlContext` traits instead.

**Breaking:** `GlContext` trait is now a part of the `prelude`.

Automatically cleanup the `EGLDisplay` when `EGL_KHR_display_reference` is present.

Add `api::egl::Display::terminate` to terminate the display when glutin doesn't manage it.

Pick the latest available profile on macOS.

Fix `GlProfile::Core` requesting without explicit version.

**Breaking:** Bump MSRV from `1.57` to `1.60`.

**Breaking:** `GlConfig::sample_buffers` now called `GlConfig::num_samples` and returns the amount of samples in multisample buffer.

**Breaking:** `ConfigTemplateBuilder::with_sample_buffers` now called `ConfigTemplateBuilder::with_multisampling`.

Fixed soundness issues with `Surface` MT safety, since before `EGLSurface` could be sent to a different thread, which is not safe.

The ios support was removed for the lack of maintainance for now. In case there's a need for it, contributions are welcome.

The context creation is no longer limited to winit's supported platforms.

The underlying Api providers are publically exposed now, so glutin could be used with just e.g. `EGL`.

Fallback to `Surface::swap_buffers` when `Surface::swap_buffers_with_damage` is not supported on `EGL`.

Added `Clone` to `ContextBuilder`.

Added headless example.

Removed internal code relating to libcaca.

Implemented `Debug` on all public facing types.

Dropping contexts on platforms using egl and/or glx no longer resets the current context, if the context dropped wasn't the current context.