Validator services adjust with system time

[pawanjay176]

Issue Addressed

Fixes #2052

Proposed Changes

Instead of running a repeated interval timer, the duties, attestation and fork services sleep for the required duration until the next slot/epoch and then run spawn their respective tasks.

[paulhauner]

You should be able to fix the clippy lints by merging in unstable :)

[paulhauner]

Just checking to make sure this is still a draft and not ready-for-review :)

[pawanjay176]

Sorry, I lost sight of this guy 😅 Will merge unstable and do some more testing on this.

[paulhauner]

Just a few comments. There's also another timer here:

lighthouse/validator_client/src/notifier.rs

Line 27 in 46920a8

interval.tick().await;

I haven't had a chance to check out the simulator with 1s slot times, but I'll check that out once these comments are addressed :)

[paulhauner]

Just double-checking that this isn't ready for review :)

[pawanjay176]

Sorry forgot to mark it. It is ready for review!

[michaelsproul]

I'm really keen to get this merged @pawanjay176, it looks great, but @paulhauner just went and revamped the whole duties service in the meantime 😩

There's a user on Discord who needs this PR, I think..

[paulhauner]

I can take care of merging this down once we get my optimise PR in :)

[paulhauner]

Closing this since I merged it into #2243. Thanks for your work @pawanjay176!