Verify chronos/TokenBucket updated replenish algorithm

[NagyZoltanPeter]

This PR intended to nim-chronos updated TokenBucket.

nim-chronos vendor submodule is updated to working branch chore-token-bucket-unification.

With status-im/nim-chronos#582 TokenBucket is modified:

• fixed, to handle initial lastUpdate correctly
• Updated replenish algorithm to better utilize available tokens and serve small burst that spread in time.
• no braking interface changes

This PR is not meant to merge as is. Changes can only take effect with vendor bumps after nim-chronos' PR is accepted and merged.

[github-actions]

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