v3.1: streamer: set fixed RX window for all connections (backport of #9143)

[mergify]

Problem

• Streamer RX window management logic is unnecessarily complex
• We control MAX_DATA and MAX_STREAMS independently even though controlling one of them is sufficient
• Since most our logic related to streamer operates in streams, setting RX window in bytes is adding unnecessary complications to convert from streams to bytes

Summary of Changes

• Allow for 8MB MAX_DATA for all connections (enough to reach 200Mbps over 320ms RTT, reasonable connections will never be limited by this)
• Ensure the SWQOS efficiently throttles connections based on MAX_STREAMS setting

---

This is an automatic backport of pull request #9143 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of a155621 has failed:

On branch mergify/bp/v3.1/pr-9143
Your branch is up to date with 'origin/v3.1'.

You are currently cherry-picking commit a1556213d.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   streamer/src/nonblocking/quic.rs
	modified:   streamer/src/quic.rs

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   streamer/src/nonblocking/simple_qos.rs
	both modified:   streamer/src/nonblocking/swqos.rs
	both modified:   streamer/src/streamer.rs

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[t-nelson]

are we planning to fix the merge conflicts?

[alexpyattaev]

are we planning to fix the merge conflicts?

Done, also rebased to target 3.1.4

[alexpyattaev]

A bit of context for the purpose of this backport:

• this addresses some conditions where a legitimate sender with many large TXs could get throttled by MAX_DATA on a connection earlier than it could use up its stream limit (because those limits were computed somewhat differently)
• we intend to backport some adjustments to the MAX_STREAMS management in streamer as a follow-up to this one.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 97.05882% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 83.2%. Comparing base (0843de8) to head (47762e8).

Additional details and impacted files

@@            Coverage Diff            @@
##             v3.1    #9330     +/-   ##
=========================================
- Coverage    83.2%    83.2%   -0.1%     
=========================================
  Files         865      865             
  Lines      375981   375907     -74     
=========================================
- Hits       313027   312940     -87     
- Misses      62954    62967     +13     

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