Improve the view for VM/Instruction output

[jasonwilliams]

For debugging purposes it would be useful to see what our stack and instructions look like at a particular time.
Our output is quite basic currently.

Running let a = 1; for example with "vm" feature set will give you:
(cargo run --features vm ../tests/js/test.js)

[boa/src/context.rs:761] &compiler = Compiler {
    instructions: [
        DefLet(
            0,
        ),
        One,
        InitLexical(
            0,
        ),
    ],
    pool: [
        String(
            RcString(
                "a",
            ),
        ),
    ],
}

It would be good to get some better output like the below. This would be achieved by adding some output to a buffer for each action take in the match arm here: https://github.com/boa-dev/boa/blob/master/boa/src/vm/mod.rs#L54 then printing the whole buffer when its finished.

The code for doing this should be behind a flag or an argument and not ran by default.

For timing https://doc.rust-lang.org/std/time/struct.Instant.html should do the job.

Example output below

$ cargo run -- --trace
> function fibo(x) { if (x<2) return 1; return fibo(x-1)+fibo(x-2)}
00020m 00000 Return                    <empty>
undefined
> fibo(3)
00009m 00000 PushInt8 3                <empty>
00015m 00002 GetValue 'fibo'           3.0
00066m 00007 Call 1                    Function
--> call function
  module_id:0 func_id:0
00007m 00000 GetValue 'x'              <empty>
00001m 00005 PushInt8 2                3.0
00013m 00007 Lt                        2.0

...

00001m 00007 Lt                        2.0
00000m 00008 JmpIfFalse 00016          true
00000m 00013 PushInt8 1                <empty>
00167m 00015 Return                    1.0
<-- return value(1.0)
  module_id:0 func_id:2
00001m 00052 Add                       1.0
00044m 00053 Return                    3.0
<-- return value(3.0)
  module_id:0 func_id:0
00000m 00012 Return                    3.0
3
> 
   |     |     |                        | 
   |     |     |                        \- value at the top of exec stack
   |     |     \-------------------------- instruction
   |     \-------------------------------- program counter
   \-------------------------------------- execution time per inst. (in microsecs)