Fixes race conditions for the most part (fixes #6018)

Includes improvements to perf:

- Update actor reminders data structures
- Switch data field to be json.RawMessage
- Reduce code duplication & tech debt
Signed-off-by: NItalyPaleAle <43508+ItalyPaleAle@users.noreply.github.com>
Co-authored-by: NArtur Souza <asouza.pro@gmail.com>