Catchain improvements (#698)

* Fix "sgn" in fift; fix marking infinite loops as noterurn in func

* TON-P1-1: Remove unused catchain queries

* TON-P1-15: Avoid synchronization with self

* TON-P1-3, TON-P1-17: Disallow more than one candidate per src per round (to prevent flood), add checks to process_broadcast

* TON-P1-10: Fix fast/slow attempts

* TON-P1-14: Add named constants

* TON-P1-18, TON-P1-19: Alloc temporary memory in the same way as persistent memory

* TON-P1-20: Add comment to choose_blocks_to_approve

* TON-P1-16: Avoid creating two catchain blocks on need_new_block

* TON-P1-8: Add some validation to validator-engine parameters

* TON-P1-6: Don't allow sending the same block many times

Many requests for the same block are not unusual (however, there's no need to answer them all)

* TON-P1-2: Enable prohibiting dependencies from blamed nodes (2.7.5 in CatChain doc), fix processing blame proofs

* Best practices

bp-6: Fix incorrect warning
bp-7: Remove unused code
bp-8: Bring back PerfWarningTimer logging (only when no callback)
bp-9: Remove unnecessary condition
bp-11: Remove commented-out code
bp-13: Divide code in validator-session-state
Adherence to Specification: Fix typo

tl/generate/scheme/ton_api.tl

@@ -277,14 +277,10 @@ catchain.differenceFork left:catchain.block.dep right:catchain.block.dep = catch
 catchain.blockNotFound = catchain.BlockResult;
 catchain.blockResult block:catchain.block = catchain.BlockResult;
 
-catchain.sent cnt:int = catchain.Sent;
-
 ---functions---
 
 catchain.getBlock block:int256 = catchain.BlockResult;
-catchain.getBlocks blocks:(vector int256) = catchain.Sent;
 catchain.getDifference rt:(vector int) = catchain.Difference;
-catchain.getBlockHistory block:int256 height:long stop_if:(vector int256) = catchain.Sent;
 //catchain.getForkDifference src:int fork:catchain.fork = catchain.ForkDifference;
 
 ---types---