Flag WPR related errors in debug.log via SSH instead of helper plugin

[jeawhanlee]

Is your feature request related to a problem? Please describe.
Currently, we pass by the e2e helper plugin frontend to identify WPR related errors in the debug.log, This can make tests a bit slow and unnecessary since we already have SSH implementation for this.

Describe the solution you'd like
We should bypass the frontend for performing actions like this and use the SSH, preferably.

Describe alternatives you've considered
I'll suggest that we update the e2e helper plugin to accept custom wp cli command because we already have this logic there instead of downloading and reading the file via ssh, then checking for patterns related to WPR.

Additional context
Add any other context or screenshots about the feature request here.