Add a command "Go To Definition/Declaration "

Feature Request

I would love to be able to apply "Go To Declaration" when I am requesting it on a definition, and "Go To Definition" when I am requesting it on a declaration.

I foolishly thought this was the standard F12 behaviour before finding out I need to bind both and use them contextually! I imagine its trivial to implement the context switching internally and apply the correct one given the context of the request.

i.e.
IF requested on a declaration -> Go To Definition
IF requested on a definition -> Go To Decleration

My workaround currently is binding the behaviour to the "when" field inside Keybinds.json based on file endings:

    {
        "key": "F12",
        "command": "editor.action.revealDeclaration",
        "when": "editorHasDeclarationProvider && editorTextFocus && !isInEmbeddedEditor && resourceExtname =~ /\\.(cpp|cxx|cc|c\\+\\+|c)$/"
    },
    {
        "key": "F12",
        "command": "editor.action.revealDefinition",
        "when": "editorHasDefinitionProvider && editorTextFocus && !isInEmbeddedEditor && resourceExtname =~ /\\.(hpp|hxx|hh|h\\+\\+|h|inl|ipp)$/"
    },

This fails in nuanced cases such as F12 on #include lines when in a source file, this will attempt "Go To Declaration" and fail but should be using "Go To Definition". Another reason a context based command would be useful!

A native command provided by the extension would be nice.

Review the existing editor.action.revealDeclaration and editor.action.revealDefinition commands and the F12/keybinding examples in the issue. Trace the C/C++ extension's command entry points and determine how the current symbol context, including #include lines, selects the target; done means one native command consistently chooses the appropriate action.