chore: Logging plugin - admin settings improvements

[colinmurphy]

Overview

Following changes are required for the admin settings page

1. Remove time threshold
2. Reverse order of rate sampling (10, 25, 50, 75 & 100)
3. Make the event field required

[colinmurphy]

Tackling this as part of #403

[ahuseyn]

Closed by #403