1. Updating table name to be more readable.
2. Adding a column with status.
Note 1:
This table is empty in the current state so it's safe to just drop and create.
Note 2:
With the current design, we allow for `ciphertext` to be the empty string. This is the case when we need to send something to a peer but `olm` session not exist or is malformed. The alternative is making this field nullable, but this will make implementation more complex and will require a lot of additional code (mostly because of [ENG-5719](https://linear.app/comm/issue/ENG-5719/improve-pointers-handling)) so going for the empty string when ciphertext is missing.
Note 3:
We need a bit different API to this table - updated in the next diffs along with tests.
Depends on D12047