Support complex `miDebugger` commands

[anacierdem]

Feature Request

Currently launch configurations expect a single path for miDebuggerPath (as the name implies) but this creates friction if the underlying debugger requires some "pre" arguments. To give an example:

{
      "type": "cppdbg",
      "request": "launch",
      "name": "Example",
      "program": "${workspaceFolder}/...",
      "preLaunchTask": "...",
      "MIMode": "gdb",
      "miDebuggerPath": "toolbox",
      "miDebuggerArgs": "run gdb"
}

This triggers the debugger via toolbox --interpreter=mi run gdb, which is not correct as the debugger is not a single command but a compound command here.

There should be a way to provide a "debugger command" where additonal arguments are appended at the end.