Refactor[BMQT]: make QueueOptions rule-of-three complaint

[678098]

Remove 400 lines from build logs

[678098]

https://bloomberg.github.io/bde-resources/doxygen/bde_api_prod/group__bslstl__unorderedmap.html#ga010b0fbb7737d2e3a902daacda105193

From the bsl::unordered_map docs:

propagate to this object the allocator of rhs if the ALLOCATOR type has trait propagate_on_container_copy_assignment

The usual assignment operator might propagate the allocator and might not. Here, I make sure to construct the unordered map with the allocator from rhs.

[hallfox]

bsl::allocator, which the map uses, doesn't allow this propagation: https://bloomberg.github.io/bde-resources/doxygen/bde_api_prod/group__bslma__stdallocator.html

I also don't think we should be rhs's allocator in this case, if allocator propagation were to happen on copy construction the class would handle it itself. Regardless I don't think we want to grab rhs's allocator this way. From the properties of [UsesBslmaAllocator trait docs](https://bloomberg.github.io/bde-resources/doxygen/bde_api_prod/group__bslma__usesbslmaallocator.html):

• The allocator used by an object is not changed after construction (e.g., the assignment operator does not change the allocator used by an object).

So what I think we really want here is to use this's allocator to do each of these allocation operations.

[hallfox]

lgtm