added ip checksum inserter + added generics to eth_tester for setting

applications/rdma_demo/src/vhdl/rdma_demo_pkg.vhd

...ions/rdma_demo/src/vhdl/rdma_demo_roce_tester_wrapper.vhd

libraries/base/common/src/vhdl/common_network_layers_pkg.vhd

libraries/io/eth/hdllib.cfg

libraries/io/eth/src/vhdl/eth_checksum_10g.vhd

libraries/io/eth/src/vhdl/eth_ip_header_checksum.vhd

libraries/io/eth/src/vhdl/eth_tester.vhd

libraries/io/eth/src/vhdl/eth_tester_tx.vhd

libraries/io/eth/tb/vhdl/tb_eth_ip_header_checksum.vhd

libraries/io/eth/tb/vhdl/tb_tb_eth_ip_header_checksum.vhd