[FEATURE] Support Signature Help LSP feature

[rossmeier]

Hi,

thanks for the super helpful project!
Not only for vhdl functions and generics, but especially for port maps it would be amazing to be reminded of the types of values you are assigning as you go. I think the most straightforward way to implement this in LSP would be using the signature help feature, but maybe (at least for generic map and port map the inlay hint feature might be able to fulfill the same purpose.