Handle missing vitals types when calculating overall performance score

[bcoe]

Safari does not populate LCP / INP / CLS, which results in an artificially lowered web vitals score.

Solution Brainstorm

When calculating the overall score for each web vitals component we should only take into account scores that are truthy.

[getsantry]

Routing to @getsentry/product-owners-insights for triage ⏲️

[edwardgou-sentry]

PRs:
#82649
#82762
#82686
#82750