Update(DeviceProxy): Dynamically Determine Memory Allocation Size & Remove Compile-Time size Calculations (#48)

* Update(DeviceProxy): Dynamically Determine Memory Allocation Size & Remove Compile-Time size Calculations

- Modified the Device proxy class to determine memory allocation size at runtime.
- Updated all classes that include the Device proxy to use dynamic memory allocation.
- Removed compile-time memory size calculations.
- Ensured the allocated number of backend queue data structures matches the number of RO device contexts.

src/reverse_offload/backend_proxy.hpp

@@ -51,7 +51,9 @@ class BackendProxy {
   /*
    * Placement new the memory which is allocated by proxy_
    */
-  BackendProxy() { new (proxy_.get()) BackendRegister(); }
+  BackendProxy(size_t num_elems = 1) : proxy_{num_elems} {
+    new (proxy_.get()) BackendRegister();
+  }
 
   /*
    * Since placement new is called in the constructor, then