[bcat] Verify delivery cache file names as file names (AI-assisted) (#4625)

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-------------------

Problem

When opening a file in a BCAT directory, Eden validated the file name using the directory validation rules. As a result, valid file names containing '.' (e.g. "VSSetting_0.byaml") were incorrectly rejected.

Fix

Use VerifyNameValidFile instead of the directory validation routine when validating file names.

Test

Verified with Splatoon 2. Files such as "VSSetting_0.byaml" could not be opened before the change and now open successfully.

Co-authored-by: Dmr77680 <dmr77680@noreply.git.eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4625
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: lizzie <lizzie@eden-emu.dev>

src/core/hle/service/bcat/delivery_cache_file_service.cpp

@@ -39,7 +39,7 @@ Result IDeliveryCacheFileService::Open(const DirectoryName& dir_name_raw,
     LOG_DEBUG(Service_BCAT, "called, dir_name={}, file_name={}", dir_name, file_name);
 
     R_TRY(VerifyNameValidDir(dir_name_raw));
-    R_TRY(VerifyNameValidDir(file_name_raw));
+    R_TRY(VerifyNameValidFile(file_name_raw));
     R_UNLESS(current_file == nullptr, ResultEntityAlreadyOpen);
 
     const auto dir = root->GetSubdirectory(dir_name);