Improve the networking abstraction of the Platform trait

[tomaka]

This PR modifies the Platform trait exposed by light-base in order to improve the abstraction over "streams" (i.e. TCP or WebSocket connections, or WebRTC substreams).

It now allows closing the sending side, and no longer allows an unlimited amount of outgoing data.

As part of this PR, most of the AsyncStdTcpWebSocket has been rewritten in a clean way. There's no cursed background task that sends and receives messages from the front or whatnot. Instead, things are now "flat" and the socket is polled directly in the future manipulated by the networking task.

Finishing this consists in updating the wasm-node implementation of Platform as well.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
      +10359 ┊ smoldot_light::network_service::tasks::connection_task::{{closure}}::h6c0628a6fbaa3d6b
       -9857 ┊ smoldot_light::network_service::tasks::connection_task::{{closure}}::hb767739b25bffcfc
        +947 ┊ alloc::collections::btree::node::BalancingContext<K,V>::bulk_steal_right::hc9a7c8929bc95300
        +910 ┊ alloc::collections::btree::node::BalancingContext<K,V>::bulk_steal_left::he4adb7e07f6de005
        +891 ┊ <smoldot_light_wasm::platform::Platform as smoldot_light::platform::Platform>::connect::{{closure}}::hff4c435264fe0977
        -852 ┊ <smoldot_light_wasm::platform::Platform as smoldot_light::platform::Platform>::connect::{{closure}}::h7e55ac5e08de9b11
        -849 ┊ alloc::collections::btree::node::BalancingContext<K,V>::bulk_steal_right::h7f138d73241e5281
        -816 ┊ alloc::collections::btree::node::BalancingContext<K,V>::bulk_steal_left::hb6b2eb205295f8e4
        +771 ┊ alloc::collections::btree::remove::<impl alloc::collections::btree::node::Handle<alloc::collections::btree::node::NodeRef<alloc::collections::btree::node::marker::Mut,K,V,alloc::collections::btree::node::marker::Leaf>,alloc::collections::btree::node::marker::KV>>::remove_leaf_kv::h5bcb337bfe379338
        -754 ┊ alloc::collections::btree::remove::<impl alloc::collections::btree::node::Handle<alloc::collections::btree::node::NodeRef<alloc::collections::btree::node::marker::Mut,K,V,alloc::collections::btree::node::marker::Leaf>,alloc::collections::btree::node::marker::KV>>::remove_leaf_kv::hcb0c933912d08eef
        -674 ┊ alloc::collections::btree::fix::<impl alloc::collections::btree::node::NodeRef<alloc::collections::btree::node::marker::Mut,K,V,alloc::collections::btree::node::marker::LeafOrInternal>>::fix_node_through_parent::hbe241ecc34543371
        +674 ┊ alloc::collections::btree::fix::<impl alloc::collections::btree::node::NodeRef<alloc::collections::btree::node::marker::Mut,K,V,alloc::collections::btree::node::marker::LeafOrInternal>>::fix_node_through_parent::hdf67f56840f1e118
        -673 ┊ alloc::collections::btree::node::Handle<alloc::collections::btree::node::NodeRef<alloc::collections::btree::node::marker::Mut,K,V,alloc::collections::btree::node::marker::Leaf>,alloc::collections::btree::node::marker::Edge>::insert_recursing::h59d100c7be33c1de
        +669 ┊ alloc::collections::btree::node::BalancingContext<K,V>::do_merge::h97fcd7b2be0a0ba9
        +669 ┊ alloc::collections::btree::node::BalancingContext<K,V>::do_merge::hfe3dff0ce71b7107
        +629 ┊ alloc::collections::btree::map::entry::VacantEntry<K,V,A>::insert::h2411dd8eb2392f52
        -615 ┊ alloc::collections::btree::node::BalancingContext<K,V>::do_merge::h024f7a24dc61d86e
        -615 ┊ alloc::collections::btree::node::BalancingContext<K,V>::do_merge::hb6484313817647a3
        +590 ┊ <smoldot_light_wasm::platform::Platform as smoldot_light::platform::Platform>::update_stream::{{closure}}::he541593a41967f9e
        -573 ┊ alloc::collections::btree::map::entry::VacantEntry<K,V,A>::insert::h70fa25bd424545f2
       +2006 ┊ ... and 313 more.
       +4033 ┊ Σ [333 Total Rows]

[tomaka]

While updating the Platform implementation in the wasm node, I've discovered several bugs where we call *_reset on a connection or stream that has already been reset by the remote. This is now fixed.