Implemented missing file handling endpoints

Added contract update endpoint

PostFundManagement.Application/Abstractions/Services/IGrantsService.cs

@@ -25,4 +25,10 @@ public interface IGrantsService
     ValueTask<Result> CreateBudgetAsync(CreateBudgetRequest request, Guid userId, CancellationToken cancellationToken = default);
 
     ValueTask<Result> CreateAwardAsync(CreateAwardRequest request, Guid userId, CancellationToken cancellationToken = default);
+
+    ValueTask<Result<string>> GetContractUrlAsync(string contractIdHash, CancellationToken cancellationToken = default);
+    
+    ValueTask<Result> UploadContractAsync(string contractIdHash, Guid userId, IFormFile file, CancellationToken cancellationToken = default);
+    
+    ValueTask<Result> UpdateContractAsync(UpdateContractRequest request, CancellationToken cancellationToken = default);
 }