Owned pixel buffer for no-copy presentation

This is based on the API that will be used for no-copy presentation. But
wraps it in `set_buffer`.

This also fixes the Wayland buffer code to set `self.width` and
`self.height` on resize, and set the length of the shared memory file
when the buffer is created.

Co-authored-by: jtnunley <jtnunley01@gmail.com>

src/error.rs

@@ -1,8 +1,10 @@
 use raw_window_handle::{RawDisplayHandle, RawWindowHandle};
 use std::error::Error;
+use std::num::NonZeroU32;
 use thiserror::Error;
 
 #[derive(Error, Debug)]
+#[allow(missing_docs)] // TODO
 #[non_exhaustive]
 pub enum SoftBufferError {
     #[error(
@@ -27,6 +29,12 @@ pub enum SoftBufferError {
     #[error("The provided display handle is null.")]
     IncompleteDisplayHandle,
 
+    #[error("Surface size {width}x{height} out of range for backend.")]
+    SizeOutOfRange {
+        width: NonZeroU32,
+        height: NonZeroU32,
+    },
+
     #[error("Platform error")]
     PlatformError(Option<String>, Option<Box<dyn Error>>),
 }