* Accelerator: partial fullnodes
1) Node can monitor a subset of shards
2) New archive slice format (sharded)
3) Validators are still required to have all shards
4) Support partial liteservers in lite-client, blockchain explorer, tonlib
5) Proxy liteserver
* Fix compilation error
* Option "--disable-ext-msg-broadcast"
* "Get shard out queue size" query
* Move disabling ext msg broadcasts from command-line arguments to config
* Fix compilation error
* Asynchronous store_cell and gc in celldb
* Make GC in celldb work evenly over time
* Increase timeouts for downloading blocks
* Reuse blocks from previous rounds in validator session
* Use Rldp2 in FullNode for downloading persistent states and archives
* Improve logs in download-archive-slice and download-state
* Decrease delay between serializing shards
* Make CellDbIn::load_cell synchronous to avoid interfering with store_cell
---------
Co-authored-by: SpyCheese <mikle98@yandex.ru>