Use memory pressure info for watchdog terminations

### Description

As described in https://github.com/getsentry/sentry-cocoa/issues/2514 and https://github.com/getsentry/sentry-cocoa/pull/3870, we could potentially use the dispatch queue's memory pressure information to report watchdog terminations as OOMs. However, we still need to determine how reliable this information is. It's highly likely that it won't work for big increments in memory consumption, for which the watchdog quickly kills the app process, and the app has no time to receive memory pressure information. It could be that this information is useful for OOMs that slowly creep in and eat up the memory. Anyways, if we report OOMs, we need to be sure that there is one; otherwise, it will be confusing to users. Another option is to somehow identify watchdog termination events with high memory pressure in Sentry. Adding breadcrumbs isn't enough because they aren't searchable/filterable in the product.