[BUG] Stream lag value could be incorrect about valkey HOT 1 OPEN

This bug is due to the fact that the entries_read field should return 0 when it is undetermined. The current lag is determined based on entries_read.
So, there are two situations that we are clear about:

• s->max_deleted_entry_id <= cg->last_id and cg->last_id <= s.first_id
  • if cg->last_id < s.first_id then cg->entries_read = s->entries_added - s->length;
  • if cg->last_id == s.first_id then cg->entries_read = s->entries_added - s->length - 1;
• s->max_deleted_entry_id <= cg->last_id and cg->last_id == s->last_id
  • the result is cg->entries_read = s->entries_added
• otherwise: cg->entries_read = SCG_INVALID_ENTRIES_READ

In native logic, there exists an empty stream logic:

• s->length == 0 and cg->last_id < s->last_id
  • cg->entries_read = s->entries_added
    This is unreasonable because the current entries_read cannot be the same as entries_added. I suggest that We should remove this.

Based on this conclusion, I will first attempt to submit a PR. Could you please help me check if the conclusion is correct. Or what additional information do I need to provide to help everyone make a judgment. @madolson @stockholmux .tks

from valkey.