[DocDB] Add unit tests for case where min_replay_txn_start_ht update is attempted before transactions are loaded

[es1024]

Jira Link: DB-14082

Description

Unit tests need to be added for the case in #24893 where we attempt to update min_replay_txn_start_ht in memory before transactions are fully loaded.

Stack trace for the code path that runs into this is:

    @     0x55deb73a6015  yb::tablet::TransactionParticipant::Impl::RemoveTransaction()
    @     0x55deb73a77e1  yb::tablet::TransactionParticipant::Impl::RemoveUnlocked()
    @     0x55deb73bb928  yb::tablet::TransactionParticipant::Impl::ProcessReplicated()
    @     0x55deb72c723c  yb::tablet::UpdateTxnOperation::DoReplicated()
    @     0x55deb72ba66e  yb::tablet::Operation::Replicated()
    @     0x55deb72bca0d  yb::tablet::OperationDriver::ReplicationFinished()
    @     0x55deb628988b  yb::consensus::ConsensusRound::NotifyReplicationFinished()
    @     0x55deb62d812f  yb::consensus::ReplicaState::ApplyPendingOperationsUnlocked()
    @     0x55deb62d7499  yb::consensus::ReplicaState::AdvanceCommittedOpIdUnlocked()
    @     0x55deb62c0594  yb::consensus::RaftConsensus::UpdateReplica()
    @     0x55deb62a0ec3  yb::consensus::RaftConsensus::Update()
    @     0x55deb766e42e  yb::tserver::ConsensusServiceImpl::UpdateConsensus()
    @     0x55deb632fc1e  std::__1::__function::__func<>::operator()()
    @     0x55deb633084f  yb::consensus::ConsensusServiceIf::Handle()
    @     0x55deb720add0  yb::rpc::ServicePoolImpl::Handle()
    @     0x55deb7125cbf  yb::rpc::InboundCall::InboundCallTask::Run()
    @     0x55deb721a5d3  yb::rpc::(anonymous namespace)::Worker::Execute()
    @     0x55deb7ad3eb3  yb::Thread::SuperviseThread()
    @     0x7f3a204121ca  start_thread
    @     0x7f3a20663e73  __GI___clone

Issue Type

kind/enhancement

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