Add option to generate a UVM HDL Path overlay

[amykyta3]

UVM users will want to be able to access fields via backdoor paths.
This is something that ought to be automated.

Add an option to generate an additional SV package or include that contains a class definition:

class my_block_uvm_utils_t #(type T = uvm_reg_block);
    function apply_hdl_paths(T block, path_prefix="");
        ...
    endfunction
endclass

This would allow one to use the utility class/function to apply HDL paths to UVM register model nodes that correspond to the auto-generated regblock. It would be up to the user to complete the HDL path prefix string to the regblock as appropriate:

typedef my_block_uvm_utils_t #(my_block_uvm_reg_block) my_block_utils;
my_block_utils::apply_hdl_paths(my_model.path.to.inst_a, "path.to.a")
my_block_utils::apply_hdl_paths(my_model.path.to.inst_b, "path.to.b")

...which would automatically populate the UVM backdoor paths using the register model API