[air/output] Print experiment information at experiment start

[krfricke]

Why are these changes needed?

Includes #34788

This PR prints experiment information at the start of the experiment.

@scottsun94 should this also happen when rich is enabled? (Currently disabled enabled without config table).

Example:

╭───────────────────────────────────────────────────────────────────────╮
│ Configuration for experiment     easy_objective_2023-05-02_16-10-37   │
├───────────────────────────────────────────────────────────────────────┤
│ Search algorithm                 BasicVariantGenerator                │
│ Scheduler                        FIFOScheduler                        │
│ Number of trials                 10                                   │
╰───────────────────────────────────────────────────────────────────────╯

View detailed results here: /Users/kai/ray_results/easy_objective_2023-05-02_16-10-37
To visualize your results with TensorBoard, run: `tensorboard --logdir /Users/kai/ray_results/easy_objective_2023-05-02_16-10-37`

Related issue number

Closes #34920
Closes #33154

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
  • I've added any new APIs to the API Reference. For example, if I added a
    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[scottsun94]

Should this also happen when rich is enabled?

I feel like that this is orthogonal to Rich and trial table. WDYT?

[krfricke]

Should this also happen when rich is enabled?

I feel like that this is orthogonal to Rich and trial table. WDYT?

Yep SGTM - currently it's always being printed and I think that's how it should be.

[scottsun94]

Should this also happen when rich is enabled?

I feel like that this is orthogonal to Rich and trial table. WDYT?

Yep SGTM - currently it's always being printed and I think that's how it should be.

SGTM. Thanks!

[gjoliver]

cool cool!
also a couple of nits.

[gjoliver]

hey we should mark all the public APIs with @DeveloperAPI or something.
so it's very clear what functions one can override to completely customize the terminal output.
wdyt?

[krfricke]

Since it's currently experimental we don't need annotations just now (and should probably avoid them so we can continue to quickly iterate).

Before committing to the APIs, should we have a separate discussion on how and what users should be able to configure or overwrite? I don't think many people are going to write their own reporters tbh. It's more likely that they'll use configuration options to control the output, and the reporter interface is for us to implement new handlers/features if needed.