Provide CStr getters and setters for c_char pointers and arrays (#…

…831)

It is a common operation to read and write NUL-terminated C string in
the Vulkan API, yet the only helpers for that were thus far open-coded
in the `Debug` printing implementations.

Move them to separate functions that are exposed to the user, in hopes
of helping them no longer misunderstand NUL-terminated strings (see
e.g. #830).

Important to note is that the array-copy for a static-sized `c_char`
array has also been replaced with a `CStr` wrapper: this forces the user
and our implementation to have a NUL-terminator at the end of the string,
and the setter returns `Err()` when the given `CStr (with NUL-terminator)
is too large for the static-sized array it has to be written to.

Changelog.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `VK_EXT_hdr_metadata` device extension (#804)
 - Added `VK_NV_cuda_kernel_launch` device extension (#805)
 - Added `descriptor_count()` setter on `ash::vk::WriteDescriptorSet` (#809)
+- Added `*_as_c_str()` getters for `c_char` pointers and `c_char` arrays (#831)
 
 ### Changed
 
@@ -48,7 +49,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `VK_KHR_device_group_creation`: Take borrow of `Entry` in `fn new()` (#753)
 - `VK_KHR_device_group_creation`: Rename `vk::Instance`-returning function from `device()` to `instance()` (#759)
 - Windows `HANDLE` types (`HWND`, `HINSTANCE`, `HMONITOR`) are now defined as `isize` instead of `*const c_void` (#797)
-- extensions/ext/ray_tracing_pipeline: Pass indirect SBT regions as single item reference. (#829)
+- extensions/ext/ray_tracing_pipeline: Pass indirect SBT regions as single item reference (#829)
+- Replaced `c_char` array setters with `CStr` setters (#831)
 
 ### Removed