Improve variable path handling

[TwitchBronBron]

Currently we use evaluateName to store the actual expression used to look up the value, which sometimes has the temp vars generated by execute commands. We should actually store 3 different properties for each variable.

• evaluateName - will store the full expression (something the user would run from the REPL to get to the value themselves)
• executeExpression - the expression the debugger would use to get to the variable in the shortest path for the debugger (using temp var, etc)
• variablePath the path actually used to look up the variable. This is after any evaluateToTempVar actions have run.

Here are some examples:

m.top =>
    evaluateName: "m.top"
    executeExpression: "m.top"
    variablePath: "m.top"

m.top.$children => 
    evaluateName: "m.top.getChildren(-1, 0)"
    executeExpression:  "m.top.getChildren(-1, 0)"
    variablePath: "temp1" 

    [0].$children => 
        evaluateName: "m.top.getChildren(-1, 0)[0].getChildren(-1, 0)"
        executeExpression: "temp1[0].getChildren(-1,0)"
        variablePath = "temp2"

        [0].id => 
        evaluateName: "m.top.getChildren(-1, 0)[0].getChildren(-1, 0)[0].name"
        executeExpression: "temp2[0].name"
        variablePath = "temp2.0.name"