Avoid creation of hash tables in hot places when it's possible

Preconstruct alias->parameter table once when yson struct meta is build.
Use cheap bitmap for pending members.

This give improvements from:
```
BenchmarkDecode<TFlatStructLite>       24437 ns        24433 ns        29036 items_per_second=40.9277k/s
BenchmarkDecode<TFlatStructHeavy>      24807 ns        24804 ns        29581 items_per_second=40.3154k/s
BenchmarkDecode<TDeepStructLite>       88384 ns        88365 ns         7578 items_per_second=11.3167k/s
BenchmarkDecode<TDeepStructHeavy>      42440 ns        42432 ns        16215 items_per_second=23.5672k/s

```
To:
```
BenchmarkDecode<TFlatStructLite>       21807 ns        21807 ns        30352 items_per_second=45.8565k/s
BenchmarkDecode<TFlatStructHeavy>      21271 ns        21269 ns        31537 items_per_second=47.0164k/s
BenchmarkDecode<TDeepStructLite>       82886 ns        82871 ns         8935 items_per_second=12.067k/s
BenchmarkDecode<TDeepStructHeavy>      34415 ns        34413 ns        19791 items_per_second=29.0585k/s

```
These improvements more notable if other improvements are applied.

Part 4 of https://nda.ya.ru/t/E9Ji-1bm7Gwv6c
commit_hash:d94424316e2b3fcb98e9e249ca688712d53f75b7

0 files changed, 0 insertions, 0 deletions