Add profiler to bootstrap command

[Shourya742]

This PR adds command profiling to the bootstrap command. It tracks the total execution time and records cache hits for each command. It also provides the ability to export execution result to a JSON file. Integrating this with Chrome tracing could further enhance observability.

r? @Kobzol

[Kobzol]

Thank you! I don't think that we'll need JSON output for now, I think that the main output should be some lightly formatted text that will be human interpretable.

[Kobzol]

Gonna try it tomorrow.

[rust-log-analyzer]

The job pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[RUSTC-TIMING] build_helper test:false 0.683
error: variables can be used directly in the `format!` string
   --> src/bootstrap/src/utils/exec.rs:132:25
    |
132 |                         writeln!(writer, "  - Cache hit at:   {:?}", timestamp).unwrap();
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
    = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
    |
132 -                         writeln!(writer, "  - Cache hit at:   {:?}", timestamp).unwrap();
132 +                         writeln!(writer, "  - Cache hit at:   {timestamp:?}").unwrap();
    |

error: variables can be used directly in the `format!` string
   --> src/bootstrap/src/utils/exec.rs:139:25
    |
139 | /                         writeln!(
140 | |                             writer,
141 | |                             "  - Executed at:    {:?}, duration: {:.2?}",
142 | |                             timestamp, duration
143 | |                         )
    | |_________________________^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args

error: variables can be used directly in the `format!` string
   --> src/bootstrap/src/utils/exec.rs:150:28
    |
150 |                 Some(d) => format!("{:.2?}", d),
    |                            ^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
    |
150 -                 Some(d) => format!("{:.2?}", d),
150 +                 Some(d) => format!("{d:.2?}"),
    |

[RUSTC-TIMING] bootstrap test:false 9.553
error: could not compile `bootstrap` (lib) due to 3 previous errors
Build completed unsuccessfully in 0:10:19

[Kobzol]

Can you please instead implement FormatShortCmd on the fingerprint, and then use that implementation in the FomatShortCmd for the commands? To derive the short cmd from the fingerprint, instead of storing duplicated data in it. It is supposed to be a cache key, so I don't want to include additional human-readable data in it.

[Kobzol]

I don't think this is needed.