Move misplaced SPP events and metrics to EE

What does this MR do and why?

This merge request moves four Secret Push Protection (SPP) internal events and their corresponding count metrics from CE to EE, and changes their tiers to ultimate only. These events were originally placed in CE because we planned to enable Secret Push Protection for ALL public projects. That plan is no longer happening, so the events belong back in EE.

Resolves #598310 (closed).

Files moved

Events (from config/events/ to ee/config/events/):

• spp_scan_executed.yml
• spp_scan_passed.yml
• spp_push_blocked_secrets_found.yml
• spp_push_blocked_secrets_found_with_errors.yml

Metrics (from config/metrics/counts_all/ to ee/config/metrics/counts_all/):

• count_total_spp_scan_executed.yml
• count_total_spp_scan_passed.yml
• count_total_spp_push_blocked_secrets_found.yml
• count_total_spp_push_blocked_secrets_found_with_errors.yml

In all eight files, tiers is updated from [free, premium, ultimate] to [ultimate].

MR acceptance checklist

I have evaluated this MR against the MR acceptance checklist.