Comply the Optimization Detective Plugin with the Plugin Check (PCP) Plugin

[pmbaldha]

Bug Description

Check whether the Optimization Detective Plugin fully complies with the Plugin Check (PCP) plugin. If not, make it comply.

Steps to reproduce

1. Install and activate the Plugin Check (PCP) plugin from https://wordpress.org/plugins/plugin-check/.
2. Go to Admin Dashboard > Tools > Plugin Check.
3. Select the Optimization Detective plugin.
4. Tick all Categories.
5. Click on the Check it! button.
6. See the warnings which can be resolved.

Screenshots

[westonruter]

To be addressed by #2048

[swissspidy]

Let's track all of these issues in a single issue, #2043