Cross-Shard Congestion Control (#539)

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## NEP Status *(Updated by NEP Moderators)*

**Status**: Approved

**Meeting Recording:**
https://www.youtube.com/watch?v=O1MOBmxKqhI

Protocol Work Group voting indications (❔ | 👍 | 👎 ):

* 👍 @birchmd:
#539 (review)
* 👍 @mfornet:
#539 (review)
* 👍 @mm-near:
#539 (comment)
* 👍 @bowenwang1996:
#539 (comment)

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Co-authored-by: wacban <[email protected]>
Co-authored-by: robin-near <[email protected]>
Co-authored-by: Marcelo Fornet <[email protected]>
Co-authored-by: Michael Birch <[email protected]>
Co-authored-by: Lyudmil Ivanov <[email protected]>