Merge remote-tracking branch 'origin/master' into temp-asset-browser-catalogs

Asset Catalogs: return success from AssetCatalogService::write_to_disk

Not used yet, but it could be :)

Cleanup: asset catalogs, explicitly name parameters

No functional changes.

Fileops: call `BLI_path_slash_native()` in `BLI_dir_create_recursive()`

Make the Windows version of `BLI_dir_create_recursive()` call
`BLI_path_slash_native()` before it tries to handle the path. This
should make it possible to call it with non-native path separators.

Still under review in D12611.

Asset Catalog Tests: better path separator handling

Fixes by @LazyDodo to make the tests run on Windows.

This requires another change to get working properly, namely updating
`BLI_dir_create_recursive()` on Windows to call `BLI_path_slash_native()`
on the path before trying to create it. This will be handled in a different
commit, as it's not catalog-related.

Asset Catalog Tests: pass directory path instead of file path

Just a fix for a silly mistake.

Asset Catalogs: update explanatory comment in catalog definition file

Explain the new UUID-based format in the default comment at the top of
each catalog definition file.

Cleanup: asset catalogs, avoid shadowing field by function parameter

No functional changes.

Merge remote-tracking branch 'origin/master' into temp-asset-browser-catalogs

Asset Catalog Test: avoid copying a file to a directory

Unit tests are failing on Windows, because it cannot copy a file. This
could be because the code used `BLI_copy(src_file_path, dst_dir_path)`.
It's now rewritten to `BLI_copy(src_file_path, dst_file_path)` to test
whether that fixes things.

Asset Catalog Test: reinstate commented-out cleanup code

UUIDs: rename UUID to bUUID

Rename the C++ class to `bUUID`, following
rBaf95542df3ab6b5a9ddce4c933ef6b2230d833eb.

No functional changes.

Merge remote-tracking branch 'origin/master' into temp-asset-browser-catalogs

Asset Catalogs: include BLI_winstuff.h on Windows

`BLI_winstuff.h` is necessary on Windows to use `S_ISREG` and `S_ISDIR`
macros.

Asset Catalogs: prevent writing of empty files

Asset Catalogs: nicer temporary filename when writing

Cleanup: clarify `AssetCatalogService::write_to_disk()`

No functional changes.

Cleanup: mention `UUID_STRING_LEN` in comment

Mention that `UUID_STRING_LEN` exists in the documentation of
`BLI_uuid_format()`.

No functional changes.

Asset Catalogs: defer writing of catalog definitions

Instead of writing the catalog definition file (CDF) immediately after
creating a new catalog, wait until the `write_to_disk(...)` function is
called.

As a result, it's now also possible to create an `AssetCatalogService`
without passing it an asset library root path (for example when creating
catalogs in a not-yet-saved blend file and without having an asset
library opened/configured/selected).

Cleanup: move AssetCatalogDefinitionFile functions together

No functional changes.