Commit MWS backend source tree

The ASP.NET Core solution (mws.api/mws.application/mws.domain/
mws.infrastructure) existed only as untracked working files. Adding
it to version control, plus a .gitignore for build output and local
tooling directories, so the CQRS/mediator refactor plan has a real
git history to branch and diff against.

mws.application/Roles/IRoleService.cs

@@ -0,0 +1,10 @@
+namespace Mws.Application.Roles;
+
+public interface IRoleService
+{
+    Task<List<RoleDto>> GetRolesAsync(CancellationToken ct = default);
+    Task<RoleDto> GetRoleAsync(Guid id, CancellationToken ct = default);
+    Task<RoleDto> CreateRoleAsync(SaveRoleRequest request, CancellationToken ct = default);
+    Task<RoleDto> UpdateRoleAsync(Guid id, SaveRoleRequest request, CancellationToken ct = default);
+    Task DeleteRoleAsync(Guid id, CancellationToken ct = default);
+}