feat(cocotb): add cocotb tool

This MR adds the cocotb simulation tool to the firmware framework.

Example usage: https://gitlab.msktools.desy.de/fpgafw/projects/verif/verif_desy_vhdl/-/tree/fractional_divider

make install
make project cfg=fractional_divider_unsigned
make sim cfg=fractional_divider_unsigned
make project cfg=fractional_divider_signed
make sim cfg=fractional_divider_signed

See the branch documentation for tool-dependent flags.

https://gitlab.msktools.desy.de/fpgafw/fwk/-/blob/cocotb_tool/doc/main.adoc#user-content-cocotb-tool