DataShard: volatile transactions may get stuck after a shard restart

[snaury]

I found that when VolatileTxManager starts it erroneously doesn't add expectations for transactions with dependencies. Such transactions become stuck when other participants restart and forget about the transaction. Since transaction is waiting for decisions from other participants, but doesn't actively ask for them, these decisions will never arrive and transaction will be stuck until the affected shard is restarted again.

Investigated internally in KIKIMR-22084.